diff --git a/apps/application/flow/step_node/variable_assign_node/impl/base_variable_assign_node.py b/apps/application/flow/step_node/variable_assign_node/impl/base_variable_assign_node.py
index f1711009a47..b3397314b28 100644
--- a/apps/application/flow/step_node/variable_assign_node/impl/base_variable_assign_node.py
+++ b/apps/application/flow/step_node/variable_assign_node/impl/base_variable_assign_node.py
@@ -38,6 +38,37 @@ def out_evaluation(self, variable, value):
         else:
             self.workflow_manage.out_context[variable['fields'][1]] = value
 
+    def convert(self, val, target_type):
+        if not target_type or val is None:
+            return val
+
+        if target_type == 'json_object':
+            if isinstance(val, dict) or isinstance(val, list):
+                return val
+            return json.loads(val)
+        elif target_type == 'json_string':
+            if isinstance(val, str):
+                return val
+            return json.dumps(val, ensure_ascii=False)
+        elif target_type == 'string':
+            if isinstance(val, str):
+                return val
+            return str(val)
+        elif target_type == 'int':
+            if isinstance(val, int):
+                return val
+            return int(val)
+        elif target_type == 'float':
+            if isinstance(val, float):
+                return val
+            return float(val)
+        elif target_type == 'boolean':
+            if isinstance(val, bool):
+                return val
+            return bool(val)
+        else:
+            return val
+
     def handle(self, variable, evaluation):
         result = {
             'name': variable['name'],
@@ -49,19 +80,27 @@ def handle(self, variable, evaluation):
                     val = variable['value']
                 else:
                     val = json.loads(variable['value'])
+                val = self.convert(val, variable.get('target_type'))
                 evaluation(variable, val)
                 result['output_value'] = variable['value'] = val
             elif variable['type'] == 'string':
                 # 变量解析 例如：{{global.xxx}}
                 val = self.workflow_manage.generate_prompt(variable['value'])
+                val = self.convert(val, variable.get('target_type'))
                 evaluation(variable, val)
                 result['output_value'] = val
             else:
                 val = variable['value']
+                val = self.convert(val, variable.get('target_type'))
                 evaluation(variable, val)
                 result['output_value'] = val
+        elif variable['source'] == 'null':
+            val = None
+            evaluation(variable, val)
+            result['output_value'] = val
         else:
             reference = self.get_reference_content(variable['reference'])
+            reference = self.convert(reference, variable.get('target_type'))
             evaluation(variable, reference)
             result['output_value'] = reference
         return result
@@ -69,24 +108,26 @@ def handle(self, variable, evaluation):
     def execute(self, variable_list, **kwargs) -> NodeResult:
         #
         result_list = []
-        is_chat = False
+        contains_chat_variable = False
         for variable in variable_list:
             if 'fields' not in variable:
                 continue
+
             if 'global' == variable['fields'][0]:
                 result = self.handle(variable, self.global_evaluation)
                 result_list.append(result)
-            if 'chat' == variable['fields'][0]:
+            elif 'chat' == variable['fields'][0]:
                 result = self.handle(variable, self.chat_evaluation)
                 result_list.append(result)
-                is_chat = True
-            if 'loop' == variable['fields'][0]:
+                contains_chat_variable = True
+            elif 'loop' == variable['fields'][0]:
                 result = self.handle(variable, self.loop_evaluation)
                 result_list.append(result)
-            if 'output' == variable['fields'][0]:
+            elif 'output' == variable['fields'][0]:
                 result = self.handle(variable, self.out_evaluation)
                 result_list.append(result)
-        if is_chat:
+
+        if contains_chat_variable:
             from application.flow.loop_workflow_manage import LoopWorkflowManage
             if isinstance(self.workflow_manage, LoopWorkflowManage):
                 self.workflow_manage.parentWorkflowManage.get_chat_info().set_chat_variable(
diff --git a/ui/src/locales/lang/en-US/workflow.ts b/ui/src/locales/lang/en-US/workflow.ts
index 939706357f9..13aea3091d9 100644
--- a/ui/src/locales/lang/en-US/workflow.ts
+++ b/ui/src/locales/lang/en-US/workflow.ts
@@ -317,6 +317,8 @@ You are a master of problem optimization, adept at accurately inferring user int
       label: 'Variable Assign',
       text: 'Update the value of the global variable',
       assign: 'Set Value',
+      convertType: 'Convert type',
+      doNotConvert: 'Do not convert',
     },
     variableAggregationNode: {
       label: 'Variable Aggregation',
diff --git a/ui/src/locales/lang/zh-CN/workflow.ts b/ui/src/locales/lang/zh-CN/workflow.ts
index 79164f83bff..1efb31645b3 100644
--- a/ui/src/locales/lang/zh-CN/workflow.ts
+++ b/ui/src/locales/lang/zh-CN/workflow.ts
@@ -316,6 +316,8 @@ export default {
       label: '变量赋值',
       text: '更新全局变量的值',
       assign: '赋值',
+      convertType: '转换类型',
+      doNotConvert: '不转换',
     },
     mcpNode: {
       label: 'MCP 调用',
diff --git a/ui/src/locales/lang/zh-Hant/workflow.ts b/ui/src/locales/lang/zh-Hant/workflow.ts
index 326b8c5e863..a48464a886a 100644
--- a/ui/src/locales/lang/zh-Hant/workflow.ts
+++ b/ui/src/locales/lang/zh-Hant/workflow.ts
@@ -316,6 +316,8 @@ export default {
       label: '變數賦值',
       text: '更新全域變數的值',
       assign: '賦值',
+      convertType: '轉換類型',
+      doNotConvert: '不轉換',
     },
     variableAggregationNode: {
       label: '變量聚合',
diff --git a/ui/src/workflow/nodes/variable-assign-node/index.ts b/ui/src/workflow/nodes/variable-assign-node/index.ts
index 567bf425ae1..6c50d4b73cd 100644
--- a/ui/src/workflow/nodes/variable-assign-node/index.ts
+++ b/ui/src/workflow/nodes/variable-assign-node/index.ts
@@ -7,8 +7,14 @@ class VariableAssignNode extends AppNode {
   }
 }
 
+class VariableAssignModel extends AppNodeModel {
+  get_width() {
+    return 450
+  }
+}
+
 export default {
   type: 'variable-assign-node',
-  model: AppNodeModel,
+  model: VariableAssignModel,
   view: VariableAssignNode
 }
diff --git a/ui/src/workflow/nodes/variable-assign-node/index.vue b/ui/src/workflow/nodes/variable-assign-node/index.vue
index a455730e0d6..a78b477e8f3 100644
--- a/ui/src/workflow/nodes/variable-assign-node/index.vue
+++ b/ui/src/workflow/nodes/variable-assign-node/index.vue
@@ -45,6 +45,7 @@
             <el-select :teleported="false" v-model="item.source" size="small" style="width: 85px">
               <el-option :label="$t('workflow.variable.Referencing')" value="referencing" />
               <el-option :label="$t('common.custom')" value="custom" />
+              <el-option label="null" value="null" />
             </el-select>
           </div>
 
@@ -67,6 +68,7 @@
             </el-select>
 
             <el-form-item
+              class="w-full"
               v-if="item.type === 'string'"
               :prop="'variable_list.' + index + '.value'"
               :rules="{
@@ -76,6 +78,7 @@
               }"
             >
               <el-input
+                class="w-full"
                 v-model="item.value"
                 :placeholder="$t('common.inputPlaceholder')"
                 show-word-limit
@@ -120,10 +123,8 @@
               <CodemirrorEditor
                 title="JSON"
                 v-model="item.value"
-                :style="{
-                  height: '100px',
-                  width: '155px',
-                }"
+                class="w-full"
+                style="height: 100px"
                 @submitDialog="(val: string) => (form_data.variable_list[index].value = val)"
               />
             </el-form-item>
@@ -141,15 +142,28 @@
                 <el-option label="false" :value="false" />
               </el-select>
             </el-form-item>
+
+            <el-select
+              v-if="item.type === 'string'"
+              v-model="item.target_type"
+              style="max-width: 120px; margin-left: 8px"
+              :placeholder="$t('workflow.nodes.variableAssignNode.convertType')"
+            >
+              <el-option v-for="item2 in targetTypeOptions" :key="item2.key" :label="item2.label" :value="item2.key" />
+            </el-select>
           </div>
-          <el-form-item v-else>
+          <el-form-item v-else-if="item.source === 'referencing'">
             <NodeCascader
               ref="nodeCascaderRef2"
               :nodeModel="nodeModel"
-              class="w-full"
+              style="width: 230px"
               :placeholder="$t('workflow.variable.placeholder')"
               v-model="item.reference"
             />
+
+            <el-select v-model="item.target_type" style="max-width: 120px; margin-left: 8px" :placeholder="$t('workflow.nodes.variableAssignNode.convertType')">
+              <el-option v-for="item2 in targetTypeOptions" :key="item2.key" :label="item2.label" :value="item2.key" />
+            </el-select>
           </el-form-item>
         </el-card>
       </template>
@@ -174,6 +188,15 @@ const workflowMode = inject('workflowMode') as WorkflowMode
 const props = defineProps<{ nodeModel: any }>()
 
 const typeOptions = ['string', 'num', 'json', 'bool']
+const targetTypeOptions = [
+  { label: t('workflow.nodes.variableAssignNode.doNotConvert'), key: '' },
+  { label: 'string', key: 'string' },
+  { label: 'int', key: 'int' },
+  { label: 'float', key: 'float' },
+  { label: 'json_object', key: 'json_object' },
+  { label: 'json_string', key: 'json_string' },
+  { label: 'boolean', key: 'boolean' },
+]
 
 const wheel = (e: any) => {
   if (e.ctrlKey === true) {