As the existing electric vehicle driving test bench adopts the mechanical flywheel inertia to simulate vehicle inertia, some problems exist in the current system, for example, large size, discontinuous regulation etc. Designs a kind of test bench which can dynamic load to EV driving system. By means of the AC electric dynamometer system and electrical inertia simulation technology, achieves road loading simulation and vehicle inertial load simulation, returns the energy to the grid and reduce energy loss, and optimizes the estimation methods of the DC bus filter capacitance and filter inductance parameters. The simulation results show that the test bench can be more accurate on dynamic loading and simulate the actual vehicle driving conditions.