Aim at repair and experiment need for diesel locomotive, an intelligent dry-resistance test-bed for the diesel locomotive auxiliary generator was designed, overall structure designs and hardware and software system key part of which were introduced. In the software system, harmonic analysis was realized by using 2-FFT method and experimental data curve was fitted based on three parameters function of sine. The dry-resistance test-bed for diesel locomotive auxiliary generator could improve the efficiency and performance test, which ensured reliable operation of the locomotive.