Theoretical and experimental research on the ablation threshold of NiTi based shape memory alloy by using the femtosecond laser micromachining system multi-pulse cumulative ablation experiments is performed on NiTi shape memory alloy specimen with different powers and scanning speed.Then a scanning electron microscope is used to observe and analyze the morphological characteristics of the ablated area.The ablation threshold values at different scanning speeds were calculated as 2.02,2.40,3.04,5.46 and 15.44 J/cm2,respectively.Besides the influence of the cumulative effect of multiple pulses on the ablation threshold of nickel-titanium alloy was studied.The results show that when the number of effective pulses is less than 220,the ablation threshold of Niti alloy decreases rapidly with the increase of the effective pulse number.But when the number of pulses is greater than 220,the pulse energy is gradually saturated,and the decreasing trend tends to be gentle and eventually stable.Finally,by comparative analysis of the causes of heat-affected zones,the relatively optimal parameters for the femtosecond laser processing of NiTi alloy are as follows:the scanning speed is 1.5 mm/s,and the average laser power of 0.8 W.