diff --git a/easyflow-modules/easyflow-module-ai/src/main/java/tech/easyflow/ai/easyagentsflow/service/WorkflowRunningParameterResolver.java b/easyflow-modules/easyflow-module-ai/src/main/java/tech/easyflow/ai/easyagentsflow/service/WorkflowRunningParameterResolver.java
index 276ed97c..c30f9371 100644
--- a/easyflow-modules/easyflow-module-ai/src/main/java/tech/easyflow/ai/easyagentsflow/service/WorkflowRunningParameterResolver.java
+++ b/easyflow-modules/easyflow-module-ai/src/main/java/tech/easyflow/ai/easyagentsflow/service/WorkflowRunningParameterResolver.java
@@ -139,7 +139,7 @@ public class WorkflowRunningParameterResolver {
     }
 
     /**
-     * 归一化工作流运行时变量，确保文件参数统一为文件对象数组。
+     * 归一化工作流运行时变量，统一文件结构并移除空图片值。
      *
      * @param content 工作流内容
      * @param variables 原始运行变量
@@ -162,7 +162,13 @@ public class WorkflowRunningParameterResolver {
             if (isFileParameter(parameter)) {
                 normalized.put(name, normalizeFileVariableValue(normalized.get(name), name));
             } else if (isImageParameter(parameter)) {
-                normalized.put(name, normalizeImageVariableValue(normalized.get(name), name));
+                Object imageValue = normalizeImageVariableValue(
+                        normalized.get(name), name);
+                if (imageValue == null) {
+                    normalized.remove(name);
+                } else {
+                    normalized.put(name, imageValue);
+                }
             }
         }
         return normalized;
@@ -683,6 +689,10 @@ public class WorkflowRunningParameterResolver {
         if (value == null) {
             return;
         }
+        if (value instanceof String stringValue
+                && !StringUtils.hasText(stringValue)) {
+            return;
+        }
         if (value instanceof Collection<?> collection) {
             for (Object item : collection) {
                 collectFileValues(item, result);
diff --git a/easyflow-modules/easyflow-module-ai/src/test/java/tech/easyflow/ai/easyagentsflow/service/WorkflowRunningParameterResolverTest.java b/easyflow-modules/easyflow-module-ai/src/test/java/tech/easyflow/ai/easyagentsflow/service/WorkflowRunningParameterResolverTest.java
index 0940d2c8..ea449154 100644
--- a/easyflow-modules/easyflow-module-ai/src/test/java/tech/easyflow/ai/easyagentsflow/service/WorkflowRunningParameterResolverTest.java
+++ b/easyflow-modules/easyflow-module-ai/src/test/java/tech/easyflow/ai/easyagentsflow/service/WorkflowRunningParameterResolverTest.java
@@ -219,6 +219,38 @@ public class WorkflowRunningParameterResolverTest {
         Assert.assertTrue(((List<?>) attachments).get(0) instanceof Map<?, ?>);
     }
 
+    /**
+     * 空文件参数应统一归一化为空数组，避免旧客户端空字符串触发格式错误。
+     *
+     * @throws Exception 反射注入失败
+     */
+    @Test
+    public void testNormalizeRuntimeVariablesShouldTreatBlankFileValuesAsEmptyList()
+            throws Exception {
+        WorkflowRunningParameterResolver resolver = newResolver();
+        Object[] emptyValues = {null, "", "   ", List.of()};
+
+        for (Object emptyValue : emptyValues) {
+            Map<String, Object> variables = new LinkedHashMap<>();
+            variables.put("attachments", emptyValue);
+
+            Map<String, Object> normalized = resolver.normalizeRuntimeVariables(
+                    workflowContentWithStartParameters(),
+                    variables);
+
+            Assert.assertEquals(List.of(), normalized.get("attachments"));
+        }
+
+        Map<String, Object> variables = new LinkedHashMap<>();
+        variables.put("attachments", List.of(
+                " ",
+                "https://files.example.com/contracts/contract.docx"));
+        List<?> normalizedFiles = (List<?>) resolver.normalizeRuntimeVariables(
+                workflowContentWithStartParameters(),
+                variables).get("attachments");
+        Assert.assertEquals(1, normalizedFiles.size());
+    }
+
     /**
      * 文件参数应接受远程 URL 字符串数组并自动提取文件名。
      *
@@ -446,6 +478,30 @@ public class WorkflowRunningParameterResolverTest {
         Assert.assertEquals("https://example.com/image.png", image.get("url"));
     }
 
+    /**
+     * 空图片参数应从运行变量中移除，避免向执行引擎的并发 Map 写入 null。
+     *
+     * @throws Exception 反射注入失败
+     */
+    @Test
+    public void testNormalizeRuntimeVariablesShouldRemoveBlankImageValues()
+            throws Exception {
+        WorkflowRunningParameterResolver resolver = newResolver();
+        Object[] emptyValues = {null, "", "   "};
+
+        for (Object emptyValue : emptyValues) {
+            Map<String, Object> variables = new LinkedHashMap<>();
+            variables.put("image_input", emptyValue);
+
+            Map<String, Object> normalized = resolver.normalizeRuntimeVariables(
+                    workflowContentWithImageStartParameter(),
+                    variables);
+
+            Assert.assertFalse(normalized.containsKey("image_input"));
+            Assert.assertFalse(normalized.containsValue(null));
+        }
+    }
+
     /**
      * 运行入口不应接收 Data URI，避免 Base64 写入工作流状态和审计参数。
      *
diff --git a/easyflow-ui-admin/app/src/views/ai/workflow/components/WorkflowChatPage.vue b/easyflow-ui-admin/app/src/views/ai/workflow/components/WorkflowChatPage.vue
index bbee2085..274bcbdb 100644
--- a/easyflow-ui-admin/app/src/views/ai/workflow/components/WorkflowChatPage.vue
+++ b/easyflow-ui-admin/app/src/views/ai/workflow/components/WorkflowChatPage.vue
@@ -67,7 +67,10 @@ import {
 } from './workflowExecutionDetails';
 import WorkflowFinalOutput from './WorkflowFinalOutput.vue';
 import WorkflowFormItem from './WorkflowFormItem.vue';
-import { resolveWorkflowFormParameters } from './workflowFormParameters';
+import {
+  buildWorkflowFormInitialValues,
+  resolveWorkflowFormParameters,
+} from './workflowFormParameters';
 import {
   buildWorkflowFormParameterSummaries,
   buildWorkflowFormSubmissionImages,
@@ -349,24 +352,7 @@ async function resolveSharedWorkflowId() {
 }
 
 function initializeAdditionalValues() {
-  const values: Record<string, any> = {};
-  for (const parameter of additionalParameters.value) {
-    const defaultValue = parameter.defaultValue;
-    if (
-      parameter.contentType === 'file' &&
-      (defaultValue === null ||
-        defaultValue === undefined ||
-        defaultValue === '')
-    ) {
-      values[parameter.name] = [];
-    } else if (Array.isArray(defaultValue)) {
-      values[parameter.name] = [...defaultValue];
-    } else if (defaultValue && typeof defaultValue === 'object') {
-      values[parameter.name] = { ...defaultValue };
-    } else {
-      values[parameter.name] = defaultValue ?? '';
-    }
-  }
+  const values = buildWorkflowFormInitialValues(additionalParameters.value);
   defaultExtraValues.value = values;
   extraValues.value = values;
   parametersLocked.value = false;
diff --git a/easyflow-ui-admin/app/src/views/ai/workflow/components/__tests__/workflowFormParameters.test.ts b/easyflow-ui-admin/app/src/views/ai/workflow/components/__tests__/workflowFormParameters.test.ts
index 53261006..b16d13d8 100644
--- a/easyflow-ui-admin/app/src/views/ai/workflow/components/__tests__/workflowFormParameters.test.ts
+++ b/easyflow-ui-admin/app/src/views/ai/workflow/components/__tests__/workflowFormParameters.test.ts
@@ -1,12 +1,13 @@
 import { describe, expect, it } from 'vitest';
 
 import {
+  buildWorkflowFormInitialValues,
   resolveWorkflowFormParameters,
   resolveWorkflowParameterDisplayName,
   resolveWorkflowParameterLabel,
 } from '../workflowFormParameters';
 
-describe('resolveWorkflowFormParameters', () => {
+describe('workflowFormParameters', () => {
   it('uses the image parameter when a legacy schema still declares text', () => {
     const parameters = resolveWorkflowFormParameters({
       parameters: [
@@ -119,4 +120,33 @@ describe('resolveWorkflowFormParameters', () => {
       '流程开始 > 用户问题123',
     );
   });
+
+  it('builds initial values without submitting blank images', () => {
+    const imageDefault = {
+      sourceType: 'url',
+      url: 'https://example.com/default.png',
+    };
+    const choicesDefault = ['a'];
+    const values = buildWorkflowFormInitialValues([
+      { name: 'files', contentType: 'file', defaultValue: '   ' },
+      { name: 'image', contentType: 'image', defaultValue: '' },
+      {
+        name: 'defaultImage',
+        contentType: 'image',
+        defaultValue: imageDefault,
+      },
+      { name: 'text', contentType: 'text', defaultValue: 'hello' },
+      { name: 'choices', formType: 'checkbox', defaultValue: choicesDefault },
+    ]);
+
+    expect(values).toEqual({
+      files: [],
+      defaultImage: imageDefault,
+      text: 'hello',
+      choices: ['a'],
+    });
+    expect(values).not.toHaveProperty('image');
+    expect(values.defaultImage).not.toBe(imageDefault);
+    expect(values.choices).not.toBe(choicesDefault);
+  });
 });
diff --git a/easyflow-ui-admin/app/src/views/ai/workflow/components/workflowFormParameters.ts b/easyflow-ui-admin/app/src/views/ai/workflow/components/workflowFormParameters.ts
index e6b8a4d6..913ebb9a 100644
--- a/easyflow-ui-admin/app/src/views/ai/workflow/components/workflowFormParameters.ts
+++ b/easyflow-ui-admin/app/src/views/ai/workflow/components/workflowFormParameters.ts
@@ -136,6 +136,48 @@ function resolveDataType(type: string, contentType: string) {
   return 'String';
 }
 
+function isBlankMediaValue(value: unknown) {
+  return (
+    value === null ||
+    value === undefined ||
+    (typeof value === 'string' && value.trim() === '')
+  );
+}
+
+/**
+ * 构建发布运行表单的初始值，确保空媒体参数使用稳定的运行时语义。
+ *
+ * @param parameters 工作流运行参数
+ * @returns 可直接绑定到发布运行表单的初始值
+ */
+export function buildWorkflowFormInitialValues(parameters: any[]) {
+  const values: Record<string, any> = {};
+  for (const parameter of parameters || []) {
+    const defaultValue = parameter?.defaultValue;
+    if (
+      parameter?.contentType === 'file' &&
+      isBlankMediaValue(defaultValue)
+    ) {
+      values[parameter.name] = [];
+      continue;
+    }
+    if (
+      parameter?.contentType === 'image' &&
+      isBlankMediaValue(defaultValue)
+    ) {
+      continue;
+    }
+    if (Array.isArray(defaultValue)) {
+      values[parameter.name] = [...defaultValue];
+    } else if (defaultValue && typeof defaultValue === 'object') {
+      values[parameter.name] = { ...defaultValue };
+    } else {
+      values[parameter.name] = defaultValue ?? '';
+    }
+  }
+  return values;
+}
+
 export function resolveWorkflowFormParameters(workflowParams: any) {
   const schema = Array.isArray(workflowParams?.startFormSchema)
     ? workflowParams.startFormSchema