Method of driving axle load moment checking for roller test rig based on inertia matching was proposed. Effect of track wheel's inertia on traction and braking test was analyzed, which showed that inertia of track wheel was 6.7% of vehicle inertia. Too small inertia moment would cause large errors, and proper increase of track wheel moment of inertia was the only method to reduce the errors; According to coupled vibration between track wheel and car wheel, normal model analysis was proposed by using FEM, and the first 10 order model was obtained. The analysis showed that the first inherent vibration frequency was 12.634 Hz. In this frequency and corresponding speed of 257 km/h of railway vehicle in the rolling test, the coupled vibration occurred between track wheel and vehicle. At the speed of 127 km/h, the first-order round of wheel could cause vibration of car wheel and track wheels. During the test, avoiding running in coupled vibration for a long time would be useful for test precision.