Aiming at the problems of rapid test verification and equivalent road test accuracy of agricultural transport vehicle braking performance, a vehicle braking performance test bench was developed, which can realize the non-disassembly test of agricultural transport vehicle. Based on the energy distribution of vehicle braking process, the electromechanical inertia coupling compensation mechanism was proposed. Based on the coupling compensation of the mechanical inertia for the rotating parts and the electrical inertia of the motor output, the stepless simulation of the tested vehicle inertia was realized, and the energy transfer distribution of the agricultural transport vehicle in the braking process was matched. The vector double closed-loop control system of speed-torque dual-input motor was established to improve the control accuracy of motor output torque. Based on Matlab/Simulink, the simulation model of electromechanical inertia coupling compensation for agricultural transport vehicle-test bench was established. The output parameters of conventional braking from the simulation model were compared under pure mechanical inertia compensation and electromechanical inertia coupling compensation, which verified the effectiveness of electromechanical inertia coupling compensation mechanism. The hardware of the braking performance test bench and the distributed measurement and control system of the upper and lower machines were built, and the inertia compensation comparative tests were carried out based on a certain type of agricultural transport vehicle. The test results showed that the average deviation of the front and the rear axle velocity was 1.539km/h, and the variance of the velocity deviation was 1.730 km 2/h 2. Based on the coupling compensation of electromechanical inertia, which can match the energy transfer of the tested agricultural transport vehicle in the braking process in real time, and it can improve the effectiveness of the vehicle bench test and the accuracy of the equivalent road test.