Abstract: For usual hidden dangers in coal mine such as wear, edge tear and longitudinal tear of conveyor belt, poor automatic watering protection effect under over temperature of belt conveyor, spontaneous combustion of coal bunker and coal pile, coal bunker breakdown caused by water coal, person falling down during maintaining pit shaft, series combustion caused by poor plugging of power cable hole, locomotive transportation danger, error operation of electrical device, oil burning and so on, causes of above hidden dangers were analyzed, and corresponding preventive measures were given.