....

src/modules/examwork/view/onlineExam.vue

@@ -361,7 +361,7 @@ let validateFreezeTime = (rule, value, callback) => {
   } else if (!freezeTime.toString().match(/^[1-9]\d*|0$/)) {
     callback(new Error("只能是非负整数"));
     _this.activeName = "tab2";
-  } else if (freezeTime > duration) {
+  } else if (duration != "" && freezeTime > duration) {
     callback(new Error("交卷冻结时长不能大于考试时长"));
     _this.activeName = "tab2";
   } else {