In this paper,the use of local synthesis method,study the tooth contact analysis（ TCA） of the CRH5 traction gear by programming with MATLAB,respectively,calculate contact tracing line on the tooth surface and the graph of the transmission error of the middle point,huge end and small end respectively,and the graph is analyzed and explained,not only improves the direct use of TCA method to solve tooth contact,such as programming complex,time-consuming,and laid a good foundation for the rational design of cutting parameters of the spiral bevel gears.