diff --git a/web/app/components/workflow/constants.ts b/web/app/components/workflow/constants.ts
index 52f652e4b5742f..cc86b56df5da83 100644
--- a/web/app/components/workflow/constants.ts
+++ b/web/app/components/workflow/constants.ts
@@ -326,6 +326,7 @@ export const ITERATION_PADDING = {
   bottom: 20,
   left: 16,
 }
+export const PARALLEL_LIMIT = 10
 
 export const RETRIEVAL_OUTPUT_STRUCT = `{
   "content": "",
diff --git a/web/app/components/workflow/hooks/use-nodes-interactions.ts b/web/app/components/workflow/hooks/use-nodes-interactions.ts
index 9430a7768a910c..fabd96a3c3803b 100644
--- a/web/app/components/workflow/hooks/use-nodes-interactions.ts
+++ b/web/app/components/workflow/hooks/use-nodes-interactions.ts
@@ -17,6 +17,7 @@ import {
   useReactFlow,
   useStoreApi,
 } from 'reactflow'
+import { uniq } from 'lodash-es'
 import type { ToolDefaultValue } from '../block-selector/types'
 import type {
   Edge,
@@ -212,7 +213,7 @@ export const useNodesInteractions = () => {
     setEdges(newEdges)
     const incomesNodes = getIncomers(node, nodes, edges)
     if (incomesNodes.length) {
-      const incomesNodesOutgoersId = incomesNodes.map(incomeNode => getOutgoers(incomeNode, nodes, edges)).flat().map(outgoer => outgoer.id)
+      const incomesNodesOutgoersId = uniq(incomesNodes.map(incomeNode => getOutgoers(incomeNode, nodes, edges)).flat().map(outgoer => outgoer.id))
 
       if (incomesNodesOutgoersId.length > 1) {
         const newNodes = produce(nodes, (draft) => {
diff --git a/web/app/components/workflow/hooks/use-workflow.ts b/web/app/components/workflow/hooks/use-workflow.ts
index 4a77c734e639d6..74cbf15e4a8aa3 100644
--- a/web/app/components/workflow/hooks/use-workflow.ts
+++ b/web/app/components/workflow/hooks/use-workflow.ts
@@ -6,6 +6,7 @@ import {
 } from 'react'
 import dayjs from 'dayjs'
 import { uniqBy } from 'lodash-es'
+import { useTranslation } from 'react-i18next'
 import { useContext } from 'use-context-selector'
 import {
   getIncomers,
@@ -29,6 +30,7 @@ import {
   useWorkflowStore,
 } from '../store'
 import {
+  PARALLEL_LIMIT,
   SUPPORT_OUTPUT_VARS_NODE,
 } from '../constants'
 import { CUSTOM_NOTE_NODE } from '../note-node/constants'
@@ -59,6 +61,7 @@ export const useIsChatMode = () => {
 }
 
 export const useWorkflow = () => {
+  const { t } = useTranslation()
   const { locale } = useContext(I18n)
   const store = useStoreApi()
   const workflowStore = useWorkflowStore()
@@ -288,6 +291,14 @@ export const useWorkflow = () => {
     if (sourceNode.type === CUSTOM_NOTE_NODE || targetNode.type === CUSTOM_NOTE_NODE)
       return false
 
+    const sourceNodeOutgoers = getOutgoers(sourceNode, nodes, edges)
+
+    if (sourceNodeOutgoers.length > PARALLEL_LIMIT - 1) {
+      const { setShowTips } = workflowStore.getState()
+      setShowTips(t('workflow.common.parallelTip.limit', { num: PARALLEL_LIMIT }))
+      return false
+    }
+
     if (sourceNode && targetNode) {
       const sourceNodeAvailableNextNodes = nodesExtraData[sourceNode.data.type].availableNextNodes
       const targetNodeAvailablePrevNodes = [...nodesExtraData[targetNode.data.type].availablePrevNodes, BlockEnum.Start]
diff --git a/web/app/components/workflow/index.tsx b/web/app/components/workflow/index.tsx
index 4aebfae5a7d1d2..a42bcb6353af29 100644
--- a/web/app/components/workflow/index.tsx
+++ b/web/app/components/workflow/index.tsx
@@ -69,6 +69,7 @@ import NodeContextmenu from './node-contextmenu'
 import SyncingDataModal from './syncing-data-modal'
 import UpdateDSLModal from './update-dsl-modal'
 import DSLExportConfirmModal from './dsl-export-confirm-modal'
+import LimitTips from './limit-tips'
 import {
   useStore,
   useWorkflowStore,
@@ -320,6 +321,7 @@ const Workflow: FC<WorkflowProps> = memo(({
           />
         )
       }
+      <LimitTips />
       <ReactFlow
         nodeTypes={nodeTypes}
         edgeTypes={edgeTypes}
diff --git a/web/app/components/workflow/limit-tips.tsx b/web/app/components/workflow/limit-tips.tsx
new file mode 100644
index 00000000000000..8fd15116095d4f
--- /dev/null
+++ b/web/app/components/workflow/limit-tips.tsx
@@ -0,0 +1,32 @@
+import {
+  RiAlertFill,
+  RiCloseLine,
+} from '@remixicon/react'
+import { useStore } from './store'
+import ActionButton from '@/app/components/base/action-button'
+
+const LimitTips = () => {
+  const showTips = useStore(s => s.showTips)
+  const setShowTips = useStore(s => s.setShowTips)
+
+  if (!showTips)
+    return null
+
+  return (
+    <div className='absolute bottom-16 left-1/2 -translate-x-1/2 flex items-center rounded-xl p-2 h-10 border border-components-panel-border bg-components-panel-bg-blur shadow-md z-[9]'>
+      <div className='flex items-center justify-center w-5 h-5'>
+        <RiAlertFill className='w-4 h-4 text-text-warning-secondary' />
+      </div>
+      <div className='mx-1 px-1 system-xs-medium text-text-primary'>
+        {showTips}
+      </div>
+      <ActionButton
+        onClick={() => setShowTips('')}
+      >
+        <RiCloseLine className='w-4 h-4' />
+      </ActionButton>
+    </div>
+  )
+}
+
+export default LimitTips
diff --git a/web/app/components/workflow/nodes/_base/components/node-handle.tsx b/web/app/components/workflow/nodes/_base/components/node-handle.tsx
index 429b19b2aac46b..cbee6837c9d761 100644
--- a/web/app/components/workflow/nodes/_base/components/node-handle.tsx
+++ b/web/app/components/workflow/nodes/_base/components/node-handle.tsx
@@ -16,10 +16,15 @@ import BlockSelector from '../../../block-selector'
 import type { ToolDefaultValue } from '../../../block-selector/types'
 import {
   useAvailableBlocks,
+  useIsChatMode,
   useNodesInteractions,
   useNodesReadOnly,
 } from '../../../hooks'
-import { useStore } from '../../../store'
+import {
+  useStore,
+  useWorkflowStore,
+} from '../../../store'
+import { PARALLEL_LIMIT } from '../../../constants'
 import Tooltip from '@/app/components/base/tooltip'
 
 type NodeHandleProps = {
@@ -114,11 +119,13 @@ export const NodeSourceHandle = memo(({
 }: NodeHandleProps) => {
   const { t } = useTranslation()
   const notInitialWorkflow = useStore(s => s.notInitialWorkflow)
+  const workflowStore = useWorkflowStore()
   const [open, setOpen] = useState(false)
   const { handleNodeAdd } = useNodesInteractions()
   const { getNodesReadOnly } = useNodesReadOnly()
   const { availableNextBlocks } = useAvailableBlocks(data.type, data.isInIteration)
   const isConnectable = !!availableNextBlocks.length
+  const isChatMode = useIsChatMode()
 
   const connected = data._connectedSourceHandleIds?.includes(handleId)
   const handleOpenChange = useCallback((v: boolean) => {
@@ -126,8 +133,13 @@ export const NodeSourceHandle = memo(({
   }, [])
   const handleHandleClick = useCallback((e: MouseEvent) => {
     e.stopPropagation()
+    if (data._connectedSourceHandleIds!.length > PARALLEL_LIMIT - 1) {
+      const { setShowTips } = workflowStore.getState()
+      setShowTips(t('workflow.common.parallelTip.limit', { num: PARALLEL_LIMIT }))
+      return
+    }
     setOpen(v => !v)
-  }, [])
+  }, [data._connectedSourceHandleIds])
   const handleSelect = useCallback((type: BlockEnum, toolDefaultValue?: ToolDefaultValue) => {
     handleNodeAdd(
       {
@@ -142,7 +154,7 @@ export const NodeSourceHandle = memo(({
   }, [handleNodeAdd, id, handleId])
 
   useEffect(() => {
-    if (notInitialWorkflow && data.type === BlockEnum.Start)
+    if (notInitialWorkflow && data.type === BlockEnum.Start && !isChatMode)
       setOpen(true)
   }, [notInitialWorkflow, data.type])
 
diff --git a/web/app/components/workflow/store.ts b/web/app/components/workflow/store.ts
index e3178d0627c044..8368028185ce4f 100644
--- a/web/app/components/workflow/store.ts
+++ b/web/app/components/workflow/store.ts
@@ -164,6 +164,8 @@ type Shape = {
   setShowImportDSLModal: (showImportDSLModal: boolean) => void
   showAddBlock: boolean
   setShowAddBlock: (showAddBlock: boolean) => void
+  showTips: string
+  setShowTips: (showTips: string) => void
 }
 
 export const createWorkflowStore = () => {
@@ -266,6 +268,8 @@ export const createWorkflowStore = () => {
     setShowImportDSLModal: showImportDSLModal => set(() => ({ showImportDSLModal })),
     showAddBlock: false,
     setShowAddBlock: showAddBlock => set(() => ({ showAddBlock })),
+    showTips: '',
+    setShowTips: showTips => set(() => ({ showTips })),
   }))
 }
 
diff --git a/web/i18n/en-US/workflow.ts b/web/i18n/en-US/workflow.ts
index c6766e5f070bac..54142ab925d674 100644
--- a/web/i18n/en-US/workflow.ts
+++ b/web/i18n/en-US/workflow.ts
@@ -87,6 +87,7 @@ const translation = {
         title: 'Drag',
         desc: ' to connect',
       },
+      limit: 'Parallelism is limited to {{num}} branches.',
     },
   },
   env: {
diff --git a/web/i18n/zh-Hans/workflow.ts b/web/i18n/zh-Hans/workflow.ts
index dd1e19625088a0..1824d447531d00 100644
--- a/web/i18n/zh-Hans/workflow.ts
+++ b/web/i18n/zh-Hans/workflow.ts
@@ -87,6 +87,7 @@ const translation = {
         title: '拖拽',
         desc: '连接节点',
       },
+      limit: '并行分支限制为 {{num}} 个',
     },
   },
   env: {