diff --git a/easyflow-ui-admin/app/src/views/ai/workflow/components/WorkflowSteps.vue b/easyflow-ui-admin/app/src/views/ai/workflow/components/WorkflowSteps.vue
index 0120e811..3ca6194f 100644
--- a/easyflow-ui-admin/app/src/views/ai/workflow/components/WorkflowSteps.vue
+++ b/easyflow-ui-admin/app/src/views/ai/workflow/components/WorkflowSteps.vue
@@ -36,7 +36,8 @@ const emit = defineEmits(['resume']);
 const nodes = ref<any[]>([]);
 const nodeStatusMap = ref<Record<string, any>>({});
 const isChainError = ref(false);
-const activeName = ref<any>(props.expandAll ? [] : '');
+const activeNames = ref<string[]>([]);
+const userControlledExpansion = ref(false);
 const confirmParams = ref<any>({});
 // 定义一个对象来存储所有的 form 实例，key 为 node.key
 const formRefs = ref<Record<string, FormInstance>>({});
@@ -47,11 +48,14 @@ function shouldAutoExpandStatus(status: unknown) {
   return [1, 5, 20, 21].includes(Number(status));
 }
 
-function isExpandedNode(nodeKey: string) {
-  if (Array.isArray(activeName.value)) {
-    return activeName.value.includes(nodeKey);
+function handleManualExpansionChange() {
+  if (!props.expandAll) {
+    userControlledExpansion.value = true;
   }
-  return activeName.value === nodeKey;
+}
+
+function isExpandedNode(nodeKey: string) {
+  return activeNames.value.includes(nodeKey);
 }
 
 function hasNodePayloadChanged(previous: any, current: any) {
@@ -104,11 +108,12 @@ watch(
       }
       nodeStatusMap.value[nodeId] = currentNodeState;
       if (
+        !userControlledExpansion.value &&
         !props.expandAll &&
         previousStatus !== currentStatus &&
         shouldAutoExpandStatus(currentStatus)
       ) {
-        activeName.value = nodeId;
+        activeNames.value = [nodeId];
       }
     }
   },
@@ -121,7 +126,8 @@ watch(
     isChainError.value = false;
     confirmBtnLoading.value = false;
     chainErrMsg.value = '';
-    activeName.value = props.expandAll ? [] : '';
+    userControlledExpansion.value = false;
+    activeNames.value = [];
   },
 );
 watch(
@@ -129,9 +135,16 @@ watch(
   (newVal) => {
     const nextNodes = Array.isArray(newVal) ? [...newVal] : [];
     nodes.value = nextNodes;
-    activeName.value = props.expandAll
-      ? nextNodes.map((node: any) => node.key)
-      : '';
+
+    if (props.expandAll) {
+      activeNames.value = nextNodes.map((node: any) => node.key);
+      return;
+    }
+
+    const nodeKeys = new Set(nextNodes.map((node: any) => node.key));
+    activeNames.value = activeNames.value.filter((nodeKey) =>
+      nodeKeys.has(nodeKey),
+    );
   },
   { immediate: true },
 );
@@ -181,9 +194,9 @@ function handleConfirm(node: any) {
       <ElAlert v-if="chainErrMsg" :title="chainErrMsg" type="error" />
     </div>
     <ElCollapse
-      v-model="activeName"
-      :accordion="!props.expandAll"
+      v-model="activeNames"
       expand-icon-position="left"
+      @change="handleManualExpansionChange"
     >
       <ElCollapseItem
         v-for="node in displayNodes"
diff --git a/easyflow-ui-admin/app/src/views/ai/workflow/components/__tests__/WorkflowSteps.test.ts b/easyflow-ui-admin/app/src/views/ai/workflow/components/__tests__/WorkflowSteps.test.ts
new file mode 100644
index 00000000..a2ec2cc4
--- /dev/null
+++ b/easyflow-ui-admin/app/src/views/ai/workflow/components/__tests__/WorkflowSteps.test.ts
@@ -0,0 +1,137 @@
+import { mount } from '@vue/test-utils';
+
+import { describe, expect, it } from 'vitest';
+
+import WorkflowSteps from '../WorkflowSteps.vue';
+
+function createWorkflowNodes() {
+  return [
+    {
+      key: 'node-a',
+      label: '节点 A',
+      original: {
+        data: {},
+        type: 'llmNode',
+      },
+    },
+    {
+      key: 'node-b',
+      label: '节点 B',
+      original: {
+        data: {},
+        type: 'llmNode',
+      },
+    },
+  ];
+}
+
+function mountWorkflowSteps() {
+  return mount(WorkflowSteps, {
+    props: {
+      initSignal: false,
+      nodeJson: createWorkflowNodes(),
+      pollingData: undefined,
+      workflowId: 'workflow-1',
+    },
+    global: {
+      stubs: {
+        ConfirmItem: true,
+        ConfirmItemMulti: true,
+        ShowJson: true,
+      },
+    },
+  });
+}
+
+function getCollapseItems(wrapper: ReturnType<typeof mountWorkflowSteps>) {
+  return wrapper.findAll('.el-collapse-item');
+}
+
+describe('workflowSteps', () => {
+  it('用户手动展开或关闭后，节点刷新和轮询不会覆盖当前选择', async () => {
+    const wrapper = mountWorkflowSteps();
+
+    await wrapper.setProps({
+      pollingData: {
+        nodes: {
+          'node-a': { status: 1 },
+        },
+        status: 1,
+      },
+    });
+    expect(getCollapseItems(wrapper)[0]?.classes()).toContain('is-active');
+
+    await wrapper.setProps({
+      pollingData: {
+        nodes: {
+          'node-a': { result: { text: 'A 完成' }, status: 20 },
+          'node-b': { status: 1 },
+        },
+        status: 1,
+      },
+    });
+    expect(getCollapseItems(wrapper)[0]?.classes()).not.toContain('is-active');
+    expect(getCollapseItems(wrapper)[1]?.classes()).toContain('is-active');
+
+    await getCollapseItems(wrapper)[0]
+      ?.get('.el-collapse-item__header')
+      .trigger('click');
+    expect(getCollapseItems(wrapper)[0]?.classes()).toContain('is-active');
+    expect(getCollapseItems(wrapper)[1]?.classes()).toContain('is-active');
+
+    await wrapper.setProps({
+      nodeJson: createWorkflowNodes(),
+      pollingData: {
+        nodes: {
+          'node-a': { result: { text: 'A 完成' }, status: 20 },
+          'node-b': { result: { text: 'B 完成' }, status: 20 },
+        },
+        status: 20,
+      },
+    });
+    expect(getCollapseItems(wrapper)[0]?.classes()).toContain('is-active');
+    expect(getCollapseItems(wrapper)[1]?.classes()).toContain('is-active');
+
+    await getCollapseItems(wrapper)[0]
+      ?.get('.el-collapse-item__header')
+      .trigger('click');
+    expect(getCollapseItems(wrapper)[0]?.classes()).not.toContain('is-active');
+    expect(getCollapseItems(wrapper)[1]?.classes()).toContain('is-active');
+
+    await wrapper.setProps({
+      pollingData: {
+        nodes: {
+          'node-a': { message: '节点执行失败', status: 21 },
+          'node-b': { result: { text: 'B 完成' }, status: 20 },
+        },
+        status: 21,
+      },
+    });
+    expect(getCollapseItems(wrapper)[0]?.classes()).not.toContain('is-active');
+    expect(getCollapseItems(wrapper)[1]?.classes()).toContain('is-active');
+  });
+
+  it('新一轮试运行会清除手动选择并恢复自动跟随', async () => {
+    const wrapper = mountWorkflowSteps();
+
+    await getCollapseItems(wrapper)[1]
+      ?.get('.el-collapse-item__header')
+      .trigger('click');
+    expect(getCollapseItems(wrapper)[1]?.classes()).toContain('is-active');
+
+    await wrapper.setProps({ initSignal: true });
+    expect(
+      getCollapseItems(wrapper).every((item) => !item.classes('is-active')),
+    ).toBe(true);
+
+    await wrapper.setProps({
+      pollingData: {
+        nodes: {
+          'node-a': { status: 1 },
+        },
+        status: 1,
+      },
+    });
+    expect(getCollapseItems(wrapper)[0]?.classes()).toContain('is-active');
+  });
+});
diff --git a/easyflow-ui-admin/packages/effects/common-ui/src/components/chat-timeline/ChatTimelineItem.vue b/easyflow-ui-admin/packages/effects/common-ui/src/components/chat-timeline/ChatTimelineItem.vue
index 3647b765..93a2b5e4 100644
--- a/easyflow-ui-admin/packages/effects/common-ui/src/components/chat-timeline/ChatTimelineItem.vue
+++ b/easyflow-ui-admin/packages/effects/common-ui/src/components/chat-timeline/ChatTimelineItem.vue
@@ -7,7 +7,7 @@ import type {
   ChatTimelineToolApprovalPayload,
 } from './types';
 
-import { computed } from 'vue';
+import { computed, ref } from 'vue';
 
 import ChatThinkingBlock from '../chat-thinking/ChatThinkingBlock.vue';
 import ChatErrorNotice from './ChatErrorNotice.vue';
@@ -43,6 +43,8 @@ const emit = defineEmits<{
 const messageItem = computed(() =>
   props.item.type === 'message' ? props.item : undefined,
 );
+// 流式快照会替换消息对象，用户手动选择需要由稳定的组件实例单独保留。
+const thinkingExpandedOverrides = ref<Record<string, boolean>>({});
 
 const alignmentClass = computed(() => {
   if (props.item.type === 'message' && props.item.role === 'user') {
@@ -115,11 +117,25 @@ function updateThinkingExpanded(partId: string, expanded: boolean) {
   }
   const part = item.parts.find((current) => current.id === partId);
   if (part?.type === 'thinking') {
+    thinkingExpandedOverrides.value = {
+      ...thinkingExpandedOverrides.value,
+      [partId]: expanded,
+    };
     emit('thinkingToggle');
     part.expanded = expanded;
   }
 }
 
+function resolveThinkingExpanded(
+  part: Extract<ChatTimelineMessagePart, { type: 'thinking' }>,
+) {
+  return (
+    thinkingExpandedOverrides.value[part.id] ??
+    part.expanded ??
+    part.status === 'thinking'
+  );
+}
+
 function handleCopyAction() {
   const item = messageItem.value;
   if (!item || !props.copyAction) {
@@ -149,7 +165,7 @@ function handleCopyAction() {
         <ChatThinkingBlock
           v-if="part.type === 'thinking'"
           :content="part.content"
-          :expanded="part.expanded ?? part.status === 'thinking'"
+          :expanded="resolveThinkingExpanded(part)"
           :status="part.status"
           class="chat-timeline-item__thinking"
           readonly
diff --git a/easyflow-ui-admin/packages/effects/common-ui/src/components/chat-timeline/__tests__/ChatTimelineThinking.test.ts b/easyflow-ui-admin/packages/effects/common-ui/src/components/chat-timeline/__tests__/ChatTimelineThinking.test.ts
new file mode 100644
index 00000000..1dc1cb37
--- /dev/null
+++ b/easyflow-ui-admin/packages/effects/common-ui/src/components/chat-timeline/__tests__/ChatTimelineThinking.test.ts
@@ -0,0 +1,91 @@
+import type { ChatTimelineItem } from '../types';
+
+import { mount } from '@vue/test-utils';
+
+import { describe, expect, it } from 'vitest';
+
+import ChatTimeline from '../ChatTimeline.vue';
+
+function thinkingMessage(options?: {
+  content?: string;
+  expanded?: boolean;
+  messageStatus?: 'done' | 'streaming';
+  thinkingStatus?: 'end' | 'thinking';
+}): Extract<ChatTimelineItem, { type: 'message' }> {
+  return {
+    id: 'assistant-thinking',
+    parts: [
+      {
+        id: 'thinking-part',
+        content: options?.content ?? '分析问题',
+        expanded: options?.expanded ?? true,
+        status: options?.thinkingStatus ?? 'thinking',
+        type: 'thinking',
+      },
+    ],
+    role: 'assistant',
+    status: options?.messageStatus ?? 'streaming',
+    type: 'message',
+  };
+}
+
+describe('chat timeline thinking interaction', () => {
+  it('keeps the user expansion choice across streaming snapshots', async () => {
+    const wrapper = mount(ChatTimeline, {
+      props: {
+        items: [thinkingMessage()],
+      },
+    });
+
+    expect(wrapper.find('.chat-thinking-block__body').exists()).toBe(true);
+
+    await wrapper.get('.chat-thinking-block__trigger').trigger('click');
+    expect(wrapper.find('.chat-thinking-block__body').exists()).toBe(false);
+
+    await wrapper.setProps({
+      items: [
+        thinkingMessage({
+          content: '分析问题并继续接收思考分片',
+          expanded: true,
+        }),
+      ],
+    });
+    expect(wrapper.find('.chat-thinking-block__body').exists()).toBe(false);
+
+    await wrapper.get('.chat-thinking-block__trigger').trigger('click');
+    expect(wrapper.find('.chat-thinking-block__body').exists()).toBe(true);
+
+    await wrapper.setProps({
+      items: [
+        thinkingMessage({
+          content: '分析问题并继续接收正文分片',
+          expanded: false,
+          thinkingStatus: 'end',
+        }),
+      ],
+    });
+    expect(wrapper.find('.chat-thinking-block__body').exists()).toBe(true);
+  });
+
+  it('uses the stream default when the user has not toggled thinking', async () => {
+    const wrapper = mount(ChatTimeline, {
+      props: {
+        items: [thinkingMessage()],
+      },
+    });
+
+    expect(wrapper.find('.chat-thinking-block__body').exists()).toBe(true);
+
+    await wrapper.setProps({
+      items: [
+        thinkingMessage({
+          expanded: false,
+          messageStatus: 'done',
+          thinkingStatus: 'end',
+        }),
+      ],
+    });
+
+    expect(wrapper.find('.chat-thinking-block__body').exists()).toBe(false);
+  });
+});