diff --git a/frontend/src/components/Legend/index.tsx b/frontend/src/components/Legend/index.tsx
new file mode 100644
index 0000000..5d1891d
--- /dev/null
+++ b/frontend/src/components/Legend/index.tsx
@@ -0,0 +1,69 @@
+import { useState } from 'react';
+import { NODE_COLOR_MAP, NODE_TYPE_LABELS } from '../../config/colors';
+
+/**
+ * 图例组件
+ * 显示知识图谱中不同节点类型及其对应的颜色
+ * 支持折叠/展开展示
+ */
+export const Legend = () => {
+  const [isExpanded, setIsExpanded] = useState(true);
+
+  const nodeTypes = Object.entries(NODE_COLOR_MAP);
+
+  return (
+    <div className="absolute bottom-4 left-4 bg-white/95 backdrop-blur-sm rounded-lg shadow-lg p-4 transition-all duration-300 hover:shadow-xl z-10">
+      <div className="flex items-center justify-between mb-3">
+        <h3 className="text-sm font-semibold text-gray-700">图例</h3>
+        <button
+          onClick={() => setIsExpanded(!isExpanded)}
+          className="text-gray-400 hover:text-gray-600 transition-colors focus:outline-none"
+          aria-label={isExpanded ? '折叠图例' : '展开图例'}
+        >
+          <svg 
+            className={`w-4 h-4 transition-transform duration-300 ${isExpanded ? 'rotate-180' : ''}`}
+            fill="none" 
+            stroke="currentColor" 
+            viewBox="0 0 24 24"
+          >
+            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M19 9l-7 7-7-7" />
+          </svg>
+        </button>
+      </div>
+
+      {isExpanded && (
+        <div className="space-y-2">
+          {nodeTypes.map(([type, colors], index) => {
+            const labels = NODE_TYPE_LABELS[type] || { zh: type, en: type };
+            return (
+              <div 
+                key={type}
+                className="flex items-center space-x-3 p-2 rounded hover:bg-gray-50 transition-colors cursor-pointer"
+                style={{ animationDelay: `${index * 50}ms` }}
+              >
+                <div 
+                  className="w-4 h-4 rounded-full flex-shrink-0 shadow-sm"
+                  style={{ 
+                    backgroundColor: colors.fill,
+                    border: `1px solid ${colors.stroke}`,
+                  }}
+                />
+
+                <div className="flex flex-col min-w-0">
+                  <span className="text-xs font-medium text-gray-800 truncate">
+                    {labels.zh}
+                  </span>
+                  <span className="text-[10px] text-gray-500 truncate">
+                    {labels.en}
+                  </span>
+                </div>
+              </div>
+            );
+          })}
+        </div>
+      )}
+    </div>
+  );
+};
+
+export default Legend;
diff --git a/frontend/src/config/colors.ts b/frontend/src/config/colors.ts
index 99df291..ab0975d 100644
--- a/frontend/src/config/colors.ts
+++ b/frontend/src/config/colors.ts
@@ -11,8 +11,20 @@ export const NODE_COLOR_MAP: Record<string, { fill: string; stroke: string }> =
 // 默认节点颜色（当类型未匹配时）
 export const DEFAULT_NODE_COLORS = { fill: '#C6E5FF', stroke: '#5B8FF9' };
 
+// 节点类型双语标签映射
+export const NODE_TYPE_LABELS: Record<string, { zh: string; en: string }> = {
+  '概念': { zh: '概念', en: 'Concept' },
+  '工具': { zh: '工具', en: 'Tool' },
+  '应用': { zh: '应用', en: 'Application' },
+};
+
 // 获取节点颜色配置
 export const getNodeColors = (node: Node): { fill: string; stroke: string } => {
   if (!node.type) return DEFAULT_NODE_COLORS;
   return NODE_COLOR_MAP[node.type] || DEFAULT_NODE_COLORS;
 };
+
+// 获取节点双语标签
+export const getNodeLabels = (type: string): { zh: string; en: string } => {
+  return NODE_TYPE_LABELS[type] || { zh: type, en: type };
+};
diff --git a/frontend/src/pages/KnowledgeGraph.tsx b/frontend/src/pages/KnowledgeGraph.tsx
index a23f343..ff374dc 100644
--- a/frontend/src/pages/KnowledgeGraph.tsx
+++ b/frontend/src/pages/KnowledgeGraph.tsx
@@ -1,6 +1,7 @@
 import GraphView from '../components/GraphView/index';
 import SearchBar from '../components/SearchBar/index';
 import NodePanel from '../components/NodePanel/index';
+import Legend from '../components/Legend/index';
 import { useGraphData } from '../hooks/useGraphData';
 import { useGraphLayout } from '../hooks/useGraphLayout';
 
@@ -53,6 +54,7 @@ export const KnowledgeGraph = () => {
 
           <div className="flex-1 flex overflow-hidden">
             <main className="flex-1 bg-white relative">
+              <Legend />
               <GraphView
                 data={graphData}
                 layout={layout}
@@ -61,7 +63,7 @@ export const KnowledgeGraph = () => {
               />
               
               {hoveredNode && (
-                <div className="absolute bottom-4 left-4 bg-white/95 backdrop-blur-sm rounded-lg shadow-lg p-3 max-w-xs">
+                <div className="absolute bottom-4 right-1/2 translate-x-1/2 bg-white/95 backdrop-blur-sm rounded-lg shadow-lg p-3 max-w-sm z-20">
                   <div className="font-medium text-gray-800">{hoveredNode.label}</div>
                   {hoveredNode.type && (
                     <div className="text-sm text-gray-500">{hoveredNode.type}</div>