Abstract: For problems of single function and poor function-expanding caused by centralized control mode of current protection device of mine-used diesel locomotive, the paper put forward a design scheme of novel protection device of mine-used diesel locomotive based on CAN bus and introduced software and hardware designs of the protection device in details. Components of the protection device adopts distributed control mode and exchange data through CAN bus. The protection device can realize monitoring functions of operating parameters of mine-used diesel locomotive such as rotational speed, speed, oil pressure, gas concentration and so on, and functions of acousto-optic alarming, fault detection and pre-alarming, and has perfect function-expanding performance, which provides a completed resolution for explosion-proof diesel locomotive.