TiAl alloys were widely used in aviation,aerospace and other manufacturing fields because of their excellent properties.However,due to the physical and chemical characteristics of TiAl alloys,their cutting performance was poor,and surface cracks,burns and so on issues were easy to occur in processing.In order to study the effect of cutting parameters on surface cracks in the milling of TiAl alloy,the orthogonal experiment of TiAl alloy cutting parameters and machined surface cracks was designed.The results show that the cutting speed has the greatest influence on the surface crack of TiAl alloy milling,followed by the cutting depth and cutting width, and the feed per tooth has the least effect on the surface crack.According to genetic algorithm,taking the surface crack length as the objective function,the optimal combination of parameters are:a_e=0.2 mm,a_p=0.2003 mm/z,f_z=0.02001 mm/z,v_c=20.0004 m/min.It is found that the error between the actual machining crack length and the optimized crack length is very small,which used the milling parameters optimized by GA.The optimal method is feasible and has low error.