Abstract: The electrified railway has the high power single-phase rectifier load characteristics because of the power supply and driving mode of electric locomotive, and the power quality problems caused by traction station become more prominent. Based on the Advanced Digital Power System Simulator(ADPSS), this article takes the traction station of Ye-Chi railway accessed to East Inner Mongolia power grid for an example, the electromagnetic transient mathematical model is established, and the recursive discrete Fourier algorithm(DFT) is applied to analyze the harmonic characteristics. By establishing an electromagnetic transient harmonic control model based on active power filter, the effectiveness of the control measure is verified by simulation.