The phase transformation phenomenon due to the crystallographic change of shape memory alloys subjected to mechanical or thermal loading is very complicated. Regarding the thermo-mechanical coupling effects in shape memory alloys, in case of high  loading rates, heat generation/absorption during the forward/reverse transformation, will lead in temperature-dependent variation and consequently affects its mechanical behavior. In this paper, a numerical algorithm based on the finite element method is proposed to investigate complex mechanical, thermal, and coupled behavior of shape memory alloys, including both exclusive behaviours of these alloys, that are superelasticity and shape memory effect. Several key examples are simulated and discussed to assess the efficiency and accuracy of proposed algorithm.