您可以使用FormData对象获取表单的值，然后将画布的Blob版本附加到FormData中。
该斑点将被服务器视为文件。
不幸的是，所有浏览器仍然不支持本机canvas.toBlob()
方法，甚至值得，所有实现都不相同。
现在，所有主要的浏览器都支持toBlob方法，并且您可以在mdn上为较旧的浏览器找到一个 polyfill。
// the function to create and send our FormDatavar send = function(form, url, canvas, filename, type, quality, callback) { canvas.toBlob(function(blob){ var formData = form ? new FormData(form) : new FormData(); formData.append('file', blob, filename); var xhr = new XMLHttpRequest(); xhr.onload = callback; xhr.open('POST', url); xhr.send(formData); }, type, quality);};// How to use it //var form = document.querySelector('form'), // the form to construct the FormData, can be null or undefined to send only the image url = 'http://example.com/upload.php', // required, the url where we'll send it canvas = document.querySelector('canvas'), // required, the canvas to send filename = (new Date()).getTime() + '.jpg',// required, a filename type = 'image/jpeg', // optional, the algorithm to enpre the canvas. If omitted defaults to 'image/png' quality = .5, // optional, if the type is set to jpeg, 0-1 parameter that sets the quality of the encoding callback = function(e) {console.log(this.response);}; // optional, a callback once the xhr finishedsend(form, url, canvas, filename, type, quality, callback);PHP方面将是：
if ( isset( $_FILES["file"] ) ){ $dir = 'some/dir/'; $blob = file_get_contents($_FILES["file"]['tmp_name']); file_put_contents($dir.$_FILES["file"]["name"], $blob); }
