....

src/modules/examwork/view/onlineExam.vue

@@ -393,7 +393,7 @@ let validateSnapshotInterval = (rule, value, callback) => {
     } else if (!snapshotnterval.toString().match(/^[1-9]\d*$/)) {
       callback(new Error("只能是正整数"));
       _this.activeName = "tab4";
-    } else if (snapshotnterval > duration) {
+    } else if (duration != "" && snapshotnterval > duration) {
       callback(new Error("抓拍间隔不能大于考试时长"));
       _this.activeName = "tab4";
     } else {