È¥µôimg±êÇ©µÄstyleÊôÐÔ

var str = "<img style='ddddddddd'>"

str = str.replace(/<img[^>]*>/gi, function (match, capture) {

return match.replace(/style\s*?=\s*?([¡®"])[\s\S]*?\1/ig, '')
}))

console.log(str)