A module structure for expanding and enhancing functions of a SIM card is composed of one or more than one slots and a control chip, wherein the slot is used for emplacing a subscriber identity card, and the control chip is installed with a new application interface and application service for providing a subscriber to operate. The control chip can proceed with a change of application interface and application service through a wireless transmission, a wired transmission, an external loading device, and other related techniques for loading data, so as to facilitate the subscriber to operate additional functions provided by the control chip, other than ordinary application services provided by a common subscriber identify card, thereby achieving purposes of expanding and enhancing the functions.