The electric cable is one of the most important materials in the high speed train, accurate service life directly affects the safety of the operation of the motor car group and the operating cost of the vehicle. Due to the importance of cable life assessment, based on Arrhenius model, this paper evaluates the service life of the cable. First, the mathematical model of Arrehenius is deduced, at the same time in order to solve the problem to facilitate the corresponding simplification, the parameters of the model were obtained by the least square method. Finally, the feasibility of the method is verified by the accelerated thermal aging test of the cable.