Explosion-proof diesel engine as the main power system of underground transportation equipment in coal mine, the merits and demerits of its automatic protection device are of great significance to the safe operation of diesel locomotive and safe production in underground mine. Therefore, the automatic protection device of explosion-proof diesel engine should be able to accurately monitor the working state of diesel engine and timely parameters at work, the normal operation of diesel engine  was ensured and timely response to the factors threatening the safety of mine was made. The electric automatic protection device was introduced, the application and future development direction of explosion-proof diesel engine automatic protection device was analyzed.