The invention provides a WeChat applet user login method. The method comprises the following steps: generating a user login certificate by utilizing a wx.log function; and obtaining a user unique identifier and a user operation validity identifier from the WeChat server side according to the user login certificate, and finally obtaining an own server login certificate by utilizing the user login certificate, the user unique identifier and the user operation validity identifier so as to log in the WeChat applet. The invention discloses WeChat applet user login device and a storage device, whichare used for realizing a WeChat applet user login method. The method has the beneficial effects that the technical scheme of the invention provides a perfect, reliable and easy-to-use WeChat applet user login method, a user can quickly and safely log in the WeChat applet through the middleware, a user system in the applet can be quickly established, and the method is convenient, quick and high inpracticability.