diff --git a/app/vocabulary.py b/app/vocabulary.py
new file mode 100644
index 0000000..8d90f6e
--- /dev/null
+++ b/app/vocabulary.py
@@ -0,0 +1,163 @@
+import json
+import os
+from datetime import datetime
+
+
+class VocabularyManager:
+    def __init__(self, data_file="vocabulary_data.json"):
+        """
+        初始化词汇管理器
+        :param data_file: 词汇数据存储文件
+        """
+        self.data_file = data_file
+        self.vocabulary = {}
+        self._load_data()
+
+    def _load_data(self):
+        """从文件加载词汇数据"""
+        if os.path.exists(self.data_file):
+            try:
+                with open(self.data_file, 'r', encoding='utf-8') as f:
+                    self.vocabulary = json.load(f)
+            except (json.JSONDecodeError, FileNotFoundError):
+                self.vocabulary = {}
+
+    def _save_data(self):
+        """保存词汇数据到文件"""
+        with open(self.data_file, 'w', encoding='utf-8') as f:
+            json.dump(self.vocabulary, f, ensure_ascii=False, indent=2)
+
+    def add_word(self, word, definition, example=None, tags=None):
+        """
+        添加新单词
+        :param word: 单词
+        :param definition: 释义
+        :param example: 例句（可选）
+        :param tags: 标签列表（可选）
+        :return: 添加结果消息
+        """
+        if word.lower() in self.vocabulary:
+            return f"'{word}' already exists in vocabulary"
+
+        word_data = {
+            'definition': definition,
+            'example': example,
+            'tags': tags if tags else [],
+            'date_added': datetime.now().strftime("%Y-%m-%d %H:%M:%S"),
+            'review_count': 0,
+            'last_reviewed': None
+        }
+        self.vocabulary[word.lower()] = word_data
+        self._save_data()
+        return f"'{word}' added successfully"
+
+    def get_word(self, word):
+        """
+        获取单词详情
+        :param word: 要查询的单词
+        :return: 单词数据字典（不存在则返回None）
+        """
+        return self.vocabulary.get(word.lower())
+
+    def update_word(self, word, definition=None, example=None, tags=None):
+        """
+        更新单词信息
+        :param word: 要更新的单词
+        :param definition: 新释义（可选）
+        :param example: 新例句（可选）
+        :param tags: 新标签列表（可选）
+        :return: 更新结果消息
+        """
+        word_key = word.lower()
+        if word_key not in self.vocabulary:
+            return f"'{word}' not found in vocabulary"
+
+        if definition:
+            self.vocabulary[word_key]['definition'] = definition
+        if example is not None:  # 允许空字符串
+            self.vocabulary[word_key]['example'] = example
+        if tags is not None:  # 允许空列表
+            self.vocabulary[word_key]['tags'] = tags
+
+        self._save_data()
+        return f"'{word}' updated successfully"
+
+    def delete_word(self, word):
+        """
+        删除单词
+        :param word: 要删除的单词
+        :return: 删除结果消息
+        """
+        word_key = word.lower()
+        if word_key in self.vocabulary:
+            del self.vocabulary[word_key]
+            self._save_data()
+            return f"'{word}' deleted successfully"
+        return f"'{word}' not found in vocabulary"
+
+    def list_all_words(self):
+        """
+        获取所有单词列表
+        :return: 按添加时间排序的单词列表
+        """
+        return sorted(
+            self.vocabulary.keys(),
+            key=lambda w: self.vocabulary[w]['date_added'],
+            reverse=True
+        )
+
+    def record_review(self, word):
+        """
+        记录单词复习
+        :param word: 复习的单词
+        :return: 复习记录结果
+        """
+        word_key = word.lower()
+        if word_key in self.vocabulary:
+            self.vocabulary[word_key]['review_count'] += 1
+            self.vocabulary[word_key]['last_reviewed'] = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
+            self._save_data()
+            return f"Review recorded for '{word}'"
+        return f"'{word}' not found in vocabulary"
+
+    def search_words(self, keyword):
+        """
+        搜索包含关键字的单词
+        :param keyword: 搜索关键字
+        :return: 匹配的单词列表
+        """
+        keyword = keyword.lower()
+        return [
+            word for word, data in self.vocabulary.items()
+            if keyword in word or
+               keyword in data['definition'].lower() or
+               (data['example'] and keyword in data['example'].lower())
+        ]
+
+
+# 示例用法
+if __name__ == "__main__":
+    vm = VocabularyManager()
+
+    # 添加单词
+    print(vm.add_word("ephemeral", "短暂的，瞬息的",
+                      "Beauty is ephemeral, lasting only a few moments.",
+                      ["adjective", "literary"]))
+
+    # 获取单词详情
+    print("\nWord details:")
+    print(vm.get_word("ephemeral"))
+
+    # 更新单词
+    print(vm.update_word("ephemeral", tags=["adjective", "poetic"]))
+
+    # 记录复习
+    print(vm.record_review("ephemeral"))
+
+    # 列出所有单词
+    print("\nAll words:")
+    print(vm.list_all_words())
+
+    # 搜索单词
+    print("\nSearch results:")
+    print(vm.search_words("brief"))
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