Abstract: The test of the internal cable conductivity of the traditional bullet train is time-consuming and

laborious，which increases the probability of false detection，seriously affects the accuracy and reliability of cable

detection results of bullet trains，and greatly reduces the safety and stability of bullet trains during running. Based on the Kelvin four-wire detection resistance method，the on- resistance of the bullet train cable was measured to

determine whether there was a wire break or short circuit fault. For the detected fault cable，the fault point was

precisely located based on the time inversion method. Meanwhile，Matlab/Simulink was used for simulation test to

verify the accuracy of the fault location method proposed. Based on these above，the automatic test system for cable conductivity of bullet train was developed and applied in the field. The test results show that the automatic test system is fast，accurate，easy to operate and can significantly improve work efficiency.

      Key words: cable conductivity；Kelvin four-wire test method；time inversion method；fault location；device

development