The invention discloses a GeTe based double-function device and a manufacturing method thereof. The device comprises three layers of structures, including, a top electrode, a film dielectric layer anda bottom electrode. The top electrode is W; the film dielectric layer is a GeTe film; the bottom electrode is made of any one of ITO, FTO, ZTO, TaN and TiN. The top electrode, the film dielectric layer and the bottom electrode are prepared through a magnetron sputtering method. As the size of an operating current is controlled, different resistance state switching of the GeTe film dielectric layer is resulted and a conversional resistance change function or a complementary type resistance change function is accordingly realized. The conversional resistance change function of the GeTe based double-function device can be used as a conversional memory storage element; due to the complementary type resistance change function, a current crosstalk problem of a cross array of a resistance-variable memory can be solved efficiently; due to reasonable control of the size of the operating current, the two functions can be switched mutually, and the application scope of the device is enlarged.