Porous NiTi alloys have broad potential application in the biomedical field due to their good biocompatibility and unique mechanical properties. Porous NiTi alloys were successfully prepared by using Micro-FAST which can realize the sintering process in a short sintering time at a low cost and in a environmental-friendly way. It was found that with the increasing sintering temperature, the porosity of the porous NiTi alloys decreased firstly, then increased and slightly reduced finally. Undesired NiTi2 and Ni3Ti phases were formed and decreased gradually with a trend to form single NiTi phase. At the sintering temperature of 1100℃, the porous NiTi alloys exhibited well-distributed pores. With the increasing holding time, the porosity increased significantly to 32.2% and the pore sizes were about 100μm, which meets the requirement of human bone implants.