Abstract: Based on the evaluation of fault complexity and water inrush risk, the prevention and control system of 2 coal floor limestone water in the floor of second group of coal seams in eastern three mines in Pingdingshan mine field was proposed. The complexity of the fault structure in the study area is relatively simple as a whole, and the risk of water inrush from Cambrain limestone is small for second group of seams. The limestone water treatment is based on the method of drainage. Water hazard prevention and control system of the second group of seams consists of four subsystems:prevention and control technology, prevention and control engineering, technical support system, mine water resources and optimal allocation of water resources in the mining area. The prevention and control technology is the means, the prevention and control engineering is the core, and the mine water resources and the optimal allocation of water resources in the mining area are the development direction. By the end of 2020, the implementation of this control system will liberate 4.76 million tons of coal resources under the pressure of pressurized water, and the water pressure of the floor will drop by 0.3MPa. And the study area will fully realize the safe production of the second group of seams and the resource utilization of the mine water.