diff --git a/src/components/image-editor/EditorAgentConversation/EditorAgentConversationPanelView.test.tsx b/src/components/image-editor/EditorAgentConversation/EditorAgentConversationPanelView.test.tsx
index 805b096fa..7dc459ef1 100644
--- a/src/components/image-editor/EditorAgentConversation/EditorAgentConversationPanelView.test.tsx
+++ b/src/components/image-editor/EditorAgentConversation/EditorAgentConversationPanelView.test.tsx
@@ -446,6 +446,69 @@ describe('EditorAgentConversationPanelView', () => {
     });
   });
 
+  it('restores the draft and selected attachments when sending fails', async () => {
+    const client = createClient();
+    vi.mocked(client.sendMessage).mockRejectedValueOnce(
+      new Error('Network error'),
+    );
+
+    render(
+      <EditorAgentConversationPanelView
+        open
+        onToggleOpen={vi.fn()}
+        client={client}
+        layers={[
+          {
+            id: 'layer-1',
+            resourceId: 'resource-1',
+            title: '角色图层',
+            src: '/generated/role.png',
+            x: 0,
+            y: 0,
+            width: 512,
+            height: 512,
+            originalWidth: 512,
+            originalHeight: 512,
+            zIndex: 1,
+            sourceType: 'generated',
+          },
+        ]}
+      />,
+    );
+
+    await waitFor(() => {
+      expect(screen.getByText('已经看到画布内容')).toBeTruthy();
+    });
+
+    fireEvent.click(screen.getByRole('button', { name: '添加附件' }));
+    const attachmentDialog = screen.getByRole('dialog', {
+      name: '选择图片附件',
+    });
+    fireEvent.click(
+      within(attachmentDialog).getByRole('checkbox', {
+        name: '选择画布图片 角色图层',
+      }),
+    );
+    fireEvent.click(
+      within(attachmentDialog).getByRole('button', { name: '应用' }),
+    );
+    fireEvent.change(screen.getByLabelText('发送给画布 Agent'), {
+      target: { value: '失败后恢复这条草稿' },
+    });
+    fireEvent.click(screen.getByRole('button', { name: '发送' }));
+
+    expect(await screen.findByText('Network error')).toBeTruthy();
+    expect(
+      (screen.getByLabelText('发送给画布 Agent') as HTMLTextAreaElement).value,
+    ).toBe('失败后恢复这条草稿');
+    expect(screen.getByText('角色图层')).toBeTruthy();
+    expect(
+      within(screen.getByRole('log', { name: '画布 Agent 消息流' })).queryByText(
+        '失败后恢复这条草稿',
+      ),
+    ).toBeNull();
+  });
+
   it('preserves messages when the panel is collapsed and reopened', async () => {
     const client = createClient();
     vi.mocked(client.sendMessage).mockResolvedValue({
diff --git a/src/components/image-editor/EditorAgentConversation/useEditorAgentConversation.test.tsx b/src/components/image-editor/EditorAgentConversation/useEditorAgentConversation.test.tsx
index 84a5371c8..8f233e88c 100644
--- a/src/components/image-editor/EditorAgentConversation/useEditorAgentConversation.test.tsx
+++ b/src/components/image-editor/EditorAgentConversation/useEditorAgentConversation.test.tsx
@@ -553,7 +553,7 @@ describe('useEditorAgentConversation', () => {
     expect(onCanvasRefreshRequested).not.toHaveBeenCalled();
   });
 
-  it('handles fetch error as failed stage', async () => {
+  it('rethrows fetch errors and rolls back the optimistic message', async () => {
     const client = createClient();
     vi.mocked(client.sendMessage).mockRejectedValue(new Error('Network error'));
     const { result } = renderHook(() =>
@@ -567,10 +567,13 @@ describe('useEditorAgentConversation', () => {
     });
 
     await act(async () => {
-      await expect(result.current.sendMessage('test')).resolves.toBeUndefined();
+      await expect(result.current.sendMessage('test')).rejects.toThrow(
+        'Network error',
+      );
     });
 
     expect(result.current.errorMessage).toBe('Network error');
+    expect(result.current.messages).toHaveLength(0);
   });
 
   it('aborts the active request and resets state on stopCurrentTurn', async () => {
diff --git a/src/components/image-editor/EditorAgentConversation/useEditorAgentConversation.ts b/src/components/image-editor/EditorAgentConversation/useEditorAgentConversation.ts
index 82a1e250d..19e18d7ac 100644
--- a/src/components/image-editor/EditorAgentConversation/useEditorAgentConversation.ts
+++ b/src/components/image-editor/EditorAgentConversation/useEditorAgentConversation.ts
@@ -355,13 +355,14 @@ export function useEditorAgentConversation({
       activeRequestAbortControllerRef.current = abortController;
       setErrorMessage(null);
       setIsWaiting(true);
+      const optimisticMessage = createLocalUserMessage({
+        id: -1,
+        text,
+        attachments,
+      });
       setMessages((currentMessages) => [
         ...currentMessages,
-        createLocalUserMessage({
-          id: -1, // does not care
-          text,
-          attachments,
-        }),
+        optimisticMessage,
       ]);
 
       try {
@@ -394,6 +395,10 @@ export function useEditorAgentConversation({
         const message =
           error instanceof Error ? error.message : '发送画布 Agent 消息失败';
         setErrorMessage(message);
+        setMessages((currentMessages) =>
+          currentMessages.filter((message) => message !== optimisticMessage),
+        );
+        throw error;
       } finally {
         if (activeRequestAbortControllerRef.current === abortController) {
           activeRequestAbortControllerRef.current = null;