我也遇到这个问题，上屏是没有这个问题，但离屏就出现，网上说的，放大倍数，设置像素这些都不起作用，请问你有什么办法解决吗？？？

下面的方法都不起作用的

var myCanvas = wx.createCanvas()

var canvasKContext = myCanvas.getContext('2d')//创建离屏

var ratio = this.getPixelRatio(canvasKContext)

myCanvas.style.width = myCanvas.width + 'px'

myCanvas.style.height = myCanvas.height + 'px'

myCanvas.width = myCanvas.width * ratio

myCanvas.height = myCanvas.height * ratio

canvasKContext.scale(ratio, ratio);

canvasKContext.font = "18px Georgia"

canvasKContext.fillStyle = "#999"

canvasKContext.fillText("我是清晰的", 25 , 25 )

ctx.drawImage(myCanvas, 0, 0)//把离屏绘制到上屏上

你好，建议参考：

https://developers.weixin.qq.com/blogdetail?action=get_post_info&docid=0008acea188b48e8c4969d96056400&highline=canvas%E6%A8%A1%E7%B3%8A