Combined with simulation technology and characteristics of the EMUs back-to-back test bench, a test method of simulation line operation for EMUs traction system was put forward, in which the actual line operation data was input to simulation software, then the train running time and speed data and other data were obtained by the simulation software and input to the test system to simulate the line operation. This method provided a chance for testing the EMUs traction system on the ground, making the traction system problems discovered as soon as possible, which was much more reliable and comprehensive for verifying the performance of the traction system, and provided a reference for the traction system design.