The effects of different sintering temperature on the microstructure, microstructural evolution, surface porosity and mechanical properties of porous surface NiTi biomedical gradient alloy were investigated. The results show that the gradient alloy are consisted of complex Ti, Ni, Ti₂Ni, Ni₃Ti mixed phase and gradually transformed into NiTi phase also little Ti₂Ni、Ni₃Ti phase with increasing of the sintering temperatures. The cracks and defects at the interface between the matrix and the porous layer are gradually reduced and a stable metallurgical bonding is formed. The inner and outer grains are refined continuously, but the higher sintering temperature leads to the porosity fusion of the porous layer, resulting in the damage of the gradient structure. The porosity and the average pore size of surface layer decreases slowly. The compressive elastic modulus of the alloy changes with the sintering temperature is not obvious, while the compressive strength shows a significant increase trend. Compared with bulk NiTi alloy and porous NiTi alloy, the prepared gradient alloy not only has good interface bonding and surface pore characteristics, high compressive strength and low elastic modulus, but also has excellent super-elastic properties.