Strong electromagnetic interference occurs when the locomotive was running. Therefore, measurement errors resulted from interference exist when monitoring the rail potential only at single point. This will lead to misoperation of the protection device. An over voltage protection device based on multipoint and multi-strategy was designed. The mathematical model of rail potential distribution was built. Fuzzy neural network and multi-sensor monitoring technology were applied in this design. The emulation analysis demonstrated that the proposed device has better reliability and higher control accuracy than the single strategy approach.