diff --git a/ruoyi-ui/src/components/Process/components/nodePanel/sequenceFlow.vue b/ruoyi-ui/src/components/Process/components/nodePanel/sequenceFlow.vue
index 178cd7d4..337c0478 100644
--- a/ruoyi-ui/src/components/Process/components/nodePanel/sequenceFlow.vue
+++ b/ruoyi-ui/src/components/Process/components/nodePanel/sequenceFlow.vue
@@ -18,6 +18,7 @@
 
 <script>
 import mixinPanel from '../../common/mixinPanel'
+import {StrUtil} from '@/utils/StrUtil'
 import mixinExecutionListener from '../../common/mixinExecutionListener'
 import { commonParse, conditionExpressionParse } from '../../common/parseElement'
 export default {
@@ -69,16 +70,20 @@ export default {
   },
   watch: {
     'formData.conditionExpression': function(val) {
-      if (val) {
+      if (StrUtil.isNotBlank(val)) {
         const newCondition = this.modeler.get('moddle').create('bpmn:FormalExpression', { body: val })
         this.updateProperties({ conditionExpression: newCondition })
-      } else {
-        this.updateProperties({ conditionExpression: null })
       }
+      // else {
+      //   this.updateProperties({ conditionExpression: null })
+      // }
     },
     'formData.skipExpression': function(val) {
-      if (val === '') val = null
-      this.updateProperties({ 'flowable:skipExpression': val })
+      if (StrUtil.isNotBlank(val)) {
+        this.updateProperties({'flowable:skipExpression': val})
+      } else {
+        delete this.element.businessObject.$attrs[`flowable:skipExpression`]
+      }
     }
   },
   created() {
diff --git a/ruoyi-ui/src/components/Process/components/nodePanel/task.vue b/ruoyi-ui/src/components/Process/components/nodePanel/task.vue
index 48472a04..83f3d542 100644
--- a/ruoyi-ui/src/components/Process/components/nodePanel/task.vue
+++ b/ruoyi-ui/src/components/Process/components/nodePanel/task.vue
@@ -119,6 +119,7 @@ import executionListenerDialog from './property/executionListener'
 import taskListenerDialog from './property/taskListener'
 import multiInstanceDialog from './property/multiInstance'
 import { commonParse, userTaskParse } from '../../common/parseElement'
+import {StrUtil} from '@/utils/StrUtil'
 import FlowUser from '@/components/flow/User'
 import FlowRole from '@/components/flow/Role'
 import FlowExp from '@/components/flow/Expression'
@@ -357,7 +358,7 @@ export default {
   watch: {
     'formData.userType': function(val, oldVal) {
       const types = ['assignee', 'candidateUsers', 'candidateGroups']
-      if (oldVal) {
+      if (StrUtil.isNotBlank(oldVal)) {
         types.forEach(type => {
           delete this.element.businessObject.$attrs[`flowable:${type}`]
           delete this.formData[type]
@@ -367,67 +368,69 @@ export default {
       this.updateProperties({'flowable:userType': val})
     },
     'formData.async': function(val) {
-      if (val) {
+      if (StrUtil.isNotBlank(val)) {
         this.updateProperties({'flowable:async': val})
       }
     },
     'formData.dueDate': function(val) {
-      if (val) {
+      if (StrUtil.isNotBlank(val)) {
         this.updateProperties({'flowable:dueDate': val})
       }
     },
     'formData.formKey': function(val) {
-      if (val) {
+      if (StrUtil.isNotBlank(val)) {
         this.updateProperties({'flowable:formKey': val})
       }
     },
     'formData.priority': function(val) {
-      if (val) {
+      if (StrUtil.isNotBlank(val)) {
         this.updateProperties({'flowable:priority': val})
       }
     },
     'formData.skipExpression': function(val) {
-      if (val) {
+      if (StrUtil.isNotBlank(val)) {
         this.updateProperties({'flowable:skipExpression': val})
+      } else {
+        delete this.element.businessObject.$attrs[`flowable:skipExpression`]
       }
     },
     'formData.isForCompensation': function(val) {
-      if (val) {
+      if (StrUtil.isNotBlank(val)) {
         this.updateProperties({'isForCompensation': val})
       }
     },
     'formData.triggerable': function(val) {
-      if (val) {
+      if (StrUtil.isNotBlank(val)) {
         this.updateProperties({'flowable:triggerable': val})
       }
     },
     'formData.class': function(val) {
-      if (val) {
+      if (StrUtil.isNotBlank(val)) {
         this.updateProperties({'flowable:class': val})
       }
     },
     'formData.autoStoreVariables': function(val) {
-      if (val) {
+      if (StrUtil.isNotBlank(val)) {
         this.updateProperties({'flowable:autoStoreVariables': val})
       }
     },
     'formData.exclude': function(val) {
-      if (val) {
+      if (StrUtil.isNotBlank(val)) {
         this.updateProperties({'flowable:exclude': val})
       }
     },
     'formData.ruleVariablesInput': function(val) {
-      if (val) {
+      if (StrUtil.isNotBlank(val)) {
         this.updateProperties({'flowable:ruleVariablesInput': val})
       }
     },
     'formData.rules': function(val) {
-      if (val) {
+      if (StrUtil.isNotBlank(val)) {
         this.updateProperties({'flowable:rules': val})
       }
     },
     'formData.resultVariable': function(val) {
-      if (val) {
+      if (StrUtil.isNotBlank(val)) {
         this.updateProperties({'flowable:resultVariable': val})
       }
     }
diff --git a/ruoyi-ui/src/utils/StrUtil.js b/ruoyi-ui/src/utils/StrUtil.js
new file mode 100644
index 00000000..2c00def7
--- /dev/null
+++ b/ruoyi-ui/src/utils/StrUtil.js
@@ -0,0 +1,153 @@
+/**
+ * 字符串工具类
+ **/
+export const StrUtil = {
+  /**
+   * 字符串是否为空白 空白的定义如下： <br>
+   * 1、为null <br>
+   * 2、为不可见字符（如空格）<br>
+   * 3、""<br>
+   *
+   * @param str 被检测的字符串
+   * @return boolean 是否为空
+   */
+  isBlank: function (str) {
+    return  str === undefined || str == null || this.trim(str) === "";
+
+  },
+  /**
+   * 字符串是否为非空白 空白的定义如下： <br>
+   * 1、不为null <br>
+   * 2、不为不可见字符（如空格）<br>
+   * 3、不为""<br>
+   *
+   * @param str 被检测的字符串
+   * @return boolean 是否为非空
+   */
+  isNotBlank: function (str) {
+    // == 代表相同,=== 代表严格相同
+    return false === StrUtil.isBlank(str);
+  },
+  /**
+   * 字符串是否为空，空的定义如下:<br>
+   * 1、为null <br>
+   * 2、为""<br>
+   *
+   * @param str 被检测的字符串
+   * @return boolean 是否为空
+   */
+  isEmpty: function (str) {
+    return str == null || str === "";
+
+  },
+  /**
+   * 字符串是否为非空白 空白的定义如下： <br>
+   * 1、不为null <br>
+   * 2、不为""<br>
+   *
+   * @param str 被检测的字符串
+   * @return boolean 是否为非空
+   */
+  isNotEmpty: function (str) {
+    return !StrUtil.isEmpty(str);
+  },
+  /**
+   * 空对象转字符串
+   *
+   * @param str 被检查的字符串
+   * @return string 原字符串或者空串
+   */
+  nullToStr: function (str) {
+    if (StrUtil.isEmpty(str)) {
+      return "";
+    }
+    return str;
+  },
+  /**
+   * 空格截取
+   *
+   * @param str 截取的字符串
+   * @return string
+   */
+  trim: function (str) {
+    if (str == null) {
+      return "";
+    }
+    return str.toString().replace(/(^\s*)|(\s*$)|\r|\n/g, "");
+  },
+  /**
+   * 比较两个字符串（大小写敏感）
+   *
+   * @param str 字符串
+   * @param that 比较的字符串
+   * @return boolean
+   */
+  equals: function (str, that) {
+    return str === that;
+  },
+  /**
+   * 比较两个字符串（大小写不敏感）
+   *
+   * @param str 字符串
+   * @param that 比较的字符串
+   * @return boolean
+   */
+  equalsIgnoreCase: function (str, that) {
+    return String(str).toUpperCase() === String(that).toUpperCase();
+  },
+  /**
+   * 将字符串按指定字符分割
+   *
+   * @param str 字符串
+   * @param sep 比较的字符串
+   * @param maxLen 最大长度
+   * @return string[] 分割后的数组
+   */
+  split: function (str, sep, maxLen) {
+    if (StrUtil.isEmpty(str)) {
+      return null;
+    }
+    const value = String(str).split(sep);
+    return maxLen ? value.slice(0, maxLen - 1) : value;
+  },
+  /**
+   * 字符串格式化(%s )
+   *
+   * @param str 字符串
+   * @return 格式化后的字符串
+   */
+  sprintf: function (str) {
+    let args = arguments, flag = true, i = 1;
+    str = str.replace(/%s/g, function () {
+      const arg = args[i++];
+      if (typeof arg === 'undefined') {
+        flag = false;
+        return '';
+      }
+      return arg;
+    });
+    return flag ? str : '';
+  },
+  /**
+   * 判断字符串是否是以start开头
+   *
+   * @param str 字符串
+   * @param start 开始的字符串
+   * @return boolean
+   */
+  startWith: function (str, start) {
+    const reg = new RegExp("^" + start);
+    return reg.test(str);
+  },
+  /**
+   * 判断字符串是否是以end结尾
+   *
+   * @param str 字符串
+   * @param end 结尾的字符串
+   * @return boolean
+   */
+  endWith: function (str, end) {
+    const reg = new RegExp(end + "$");
+    return reg.test(str);
+  }
+};