The invention discloses a method for modifying memory data. The method comprises the steps of receiving a command that a user calls a number spinner JS (JavaScript) plug-in, and calling the number spinner JS plug-in; receiving a functional attribute parameter input by a user so that the number spinner JS plug-in executes a corresponding program modification memory number according to the functional attribute parameter, wherein constructing the number spinner JS plug-in based on a jQuery base includes the steps of storing all functional programs of the number spinner in a html (hypertext markup language) file structure; and receiving the functional attribute parameter input by the user through a functional attribute parameter interface and transmitting the functional attribute parameter to a corresponding functional module in the html file structure. According to the method, when the user needs the number spinner each time, the number spinner JS plug-in is called, the needed functional attribute parameter is set, the number spinner can be used, and most major browsers are compatible; and the structure and function of the spinner do not need to be written by the user. The invention also discloses a system for modifying the memory data.