Abstract: When the explosion accident occurred in the low concentration gas pipeline or the generator set is shut down for some reasons, it is bound to cause the blockage of the gas transmission pipeline, and gas drainage pump station appears to hold the pump, which directly impacts on the safety of coal production. The fire retardance overpressure release device which uses the water seal principle to automatically discharge when the pipeline pressure exceeds the set value, so as to avoid the emergence of pump suffocation. In addition, the device also has the function of fire retardance, and improves the safety of the drainage system. In this paper, the design plan of fire retardance overpressure release device is developed; then the structure design of the device and the design of the automatic control system of water level are carried out.