diff --git a/app/static/js/highlight.js b/app/static/js/highlight.js
index c9c3a02..939d691 100644
--- a/app/static/js/highlight.js
+++ b/app/static/js/highlight.js
@@ -22,39 +22,46 @@ function getWord() {
 
 function highLight() {
     if (!isHighlight) return;
+    let word = (getWord() + "").trim();
     let articleContent = document.getElementById("article").innerHTML; // innerHTML保留HTML标签来保持部分格式，且适配不同的浏览器
     let pickedWords = document.getElementById("selected-words");  // words picked to the text area
     let dictionaryWords = document.getElementById("selected-words2"); // words appearing in the user's new words list
     let allWords = dictionaryWords === null ? pickedWords.value + " " : pickedWords.value + " " + dictionaryWords.value;
     const list = allWords.split(" "); // 将所有的生词放入一个list中
+    if(word !== null && word !== "" && word !== " "){
+        let articleContent_fb2 = articleContent;
+        if(localStorage.getItem("nowWords").indexOf(word) !== -1 || localStorage.getItem("nowWords").indexOf(word.toLowerCase()) !== -1){
+            articleContent = articleContent.replace(new RegExp('<span class="highlighted">' + word + '</span>', "gi"), word);
+            pickedWords.value = localStorage.getItem("nowWords").replace(word,"");
+            document.getElementById("article").innerHTML = articleContent;
+            return;
+        }
+    }
     let totalSet = new Set();
     for (let i = 0; i < list.length; ++i) {
         list[i] = list[i].replace(/(^\W*)|(\W*$)/g, ""); // 消除单词两边的非单词字符
+        list[i] = list[i].replace('|', "");
+        list[i] = list[i].replace('?', "");
         if (list[i] != "" && !totalSet.has(list[i])) {
             // 返回所有匹配单词的集合, 正则表达式RegExp()中, "\b"匹配一个单词的边界, g 表示全局匹配, i 表示对大小写不敏感。
             let matches = new Set(articleContent.match(new RegExp("\\b" + list[i] + "\\b", "gi")));
-            if (matches.has("mark")) {
-                // 优先处理单词为 "mark" 的情况
-                totalSet = new Set(["mark", ...totalSet]);
-            }
             totalSet = new Set([...totalSet, ...matches]);
         }
     }
-    // 删除所有的mark标签,防止标签发生嵌套
-    articleContent = articleContent.replace(/<(mark)[^>]*>/gi, "");
-    articleContent = articleContent.replace(/<(\/mark)[^>]*>/gi, "");
+    // 删除所有的"<span class='highlighted'>"标签,防止标签发生嵌套
+    articleContent = articleContent.replace(new RegExp('<span class="highlighted">',"gi"), "")
+    articleContent = articleContent.replace(new RegExp("</span>","gi"), "");
     // 将文章中所有出现该单词word的地方改为："<span class='highlighted'>" + word + "</span>"。
     for (let word of totalSet) {
         articleContent = articleContent.replace(new RegExp("\\b" + word + "\\b", "g"), "<span class='highlighted'>" + word + "</span>");
     }
     document.getElementById("article").innerHTML = articleContent;
-
 }
 
 function cancelHighlighting() {
     let articleContent = document.getElementById("article").innerHTML;
-    articleContent = articleContent.replace(/<(mark)[^>]*>/gi, "");
-    articleContent = articleContent.replace(/<(\/mark)[^>]*>/gi, "");
+    articleContent = articleContent.replace(new RegExp('<span class="highlighted">',"gi"), "")
+    articleContent = articleContent.replace(new RegExp("</span>","gi"), "");
     document.getElementById("article").innerHTML = articleContent;
 }
 
diff --git a/app/test/test_bug551_XieShangHai.py b/app/test/test_bug551_XieShangHai.py
new file mode 100644
index 0000000..3e0783b
--- /dev/null
+++ b/app/test/test_bug551_XieShangHai.py
@@ -0,0 +1,30 @@
+from selenium.webdriver.common.action_chains import ActionChains
+import time
+from helper import signup
+
+def test_highlight(driver, URL):
+    try:
+        # 打开网页
+        driver.maximize_window()
+        driver.get(URL)
+    
+        # 注册
+        time.sleep(1)
+        signup(URL, driver)
+        time.sleep(2)
+
+        # 选中单词（移动鼠标到起点位置、按下鼠标左键、拖动鼠标到结束位置、释放鼠标左键、执行操作链）
+        article = driver.find_element_by_id("article")
+        actions = ActionChains(driver)
+        actions.move_to_element(article).click_and_hold().move_by_offset(450,60).release().perform()
+        time.sleep(1)
+
+        # 判断所有高亮单词是否有间隔
+        marks = driver.find_elements_by_tag_name("mark")
+        for mark in marks:
+            assert mark.value_of_css_property("padding") == '0px'
+        time.sleep(5)
+    finally:
+        # 测试结束后关闭浏览器
+        driver.quit()
+        
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