diff --git a/painter.js b/painter.js
index f24fa86..db024fb 100644
--- a/painter.js
+++ b/painter.js
@@ -662,49 +662,49 @@ Component({
 
     startPaint() {
       this.initScreenK();
+      const {
+        width,
+        height
+      } = this.properties.palette;
 
-      this.downloadImages(this.properties.palette).then(async (palette) => {
-        const {
-          width,
-          height
-        } = palette;
+      if (!width || !height) {
+        console.error(`You should set width and height correctly for painter, width: ${width}, height: ${height}`);
+        return;
+      }
 
-        if (!width || !height) {
-          console.error(`You should set width and height correctly for painter, width: ${width}, height: ${height}`);
-          return;
-        }
+      let needScale = false;
+      // 生成图片时，根据设置的像素值重新绘制
+      if (width.toPx() !== this.canvasWidthInPx) {
+        this.canvasWidthInPx = width.toPx();
+        needScale = this.properties.use2D;
+      }
+      if (this.properties.widthPixels) {
+        setStringPrototype(this.screenK, this.properties.widthPixels / this.canvasWidthInPx)
+        this.canvasWidthInPx = this.properties.widthPixels
+      }
 
-        let needScale = false;
-        // 生成图片时，根据设置的像素值重新绘制
-        if (width.toPx() !== this.canvasWidthInPx) {
-          this.canvasWidthInPx = width.toPx();
-          needScale = this.properties.use2D;
-        }
-        if (this.properties.widthPixels) {
-          setStringPrototype(this.screenK, this.properties.widthPixels / this.canvasWidthInPx)
-          this.canvasWidthInPx = this.properties.widthPixels
-        }
-
-        if (this.canvasHeightInPx !== height.toPx()) {
-          this.canvasHeightInPx = height.toPx();
-          needScale = needScale || this.properties.use2D;
-        }
-        this.setData({
-          photoStyle: `width:${this.canvasWidthInPx}px;height:${this.canvasHeightInPx}px;`,
+      if (this.canvasHeightInPx !== height.toPx()) {
+        this.canvasHeightInPx = height.toPx();
+        needScale = needScale || this.properties.use2D;
+      }
+      this.setData({
+        photoStyle: `width:${this.canvasWidthInPx}px;height:${this.canvasHeightInPx}px;`,
+      }, function () {
+        this.downloadImages(this.properties.palette).then(async palette => {
+          if (!this.photoContext) {
+            this.photoContext = await this.getCanvasContext(this.properties.use2D, 'photo');
+          }
+          if (needScale) {
+            const scale = getApp().systemInfo.pixelRatio;
+            this.photoContext.width = this.canvasWidthInPx * scale;
+            this.photoContext.height = this.canvasHeightInPx * scale;
+            this.photoContext.scale(scale, scale);
+          }
+          new Pen(this.photoContext, palette).paint(() => {
+            this.saveImgToLocal();
+          });
+          setStringPrototype(this.screenK, this.properties.scaleRatio);
         });
-        if (!this.photoContext) {
-          this.photoContext = await this.getCanvasContext(this.properties.use2D, 'photo');
-        }
-        if (needScale) {
-          const scale = getApp().systemInfo.pixelRatio;
-          this.photoContext.width = this.canvasWidthInPx * scale;
-          this.photoContext.height = this.canvasHeightInPx * scale;
-          this.photoContext.scale(scale, scale);
-        }
-        new Pen(this.photoContext, palette).paint(() => {
-          this.saveImgToLocal();
-        });
-        setStringPrototype(this.screenK, this.properties.scaleRatio);
       });
     },