diff --git a/docs/api/canvas/canvasToTempFilePath.md b/docs/api/canvas/canvasToTempFilePath.md
index e987e3cb03eed81771d4c9959ee6a2644d5b9c8d..4457e9345b837e8143ac3fec72c6da0438e5b5c2 100644
--- a/docs/api/canvas/canvasToTempFilePath.md
+++ b/docs/api/canvas/canvasToTempFilePath.md
@@ -28,6 +28,20 @@
 **示例代码**
 
 ```javascript
+// 获取到canvas对象和ctx
+let ctx = null
+let canvas = null
+const query = uni.createSelectorQuery();
+query.select('#yourcanvasid').fields({ node: true, size: true })
+  .exec((res) => {
+    canvas = res[0].node;
+    ctx = canvas.getContext("2d");
+    const dpr = uni.getSystemInfoSync().pixelRatio;
+    canvas.width = res[0].width * dpr;
+    canvas.height = res[0].height * dpr;
+    ctx.scale(dpr, dpr);
+});
+
 uni.canvasToTempFilePath({
   x: 100,
   y: 200,
@@ -35,7 +49,8 @@ uni.canvasToTempFilePath({
   height: 50,
   destWidth: 100,
   destHeight: 100,
-  canvasId: 'myCanvas',
+  canvasId: 'myCanvas', // 非 Canvas 2D能力的canvas
+  canvas: canvas, // Canvas 2D能力的canvas对象
   success: function(res) {
     // 在H5平台下，tempFilePath 为 base64
     console.log(res.tempFilePath)