Water level pressure detection device of fire hydrant

The water level pressure detection device comprises the fire hydrant, a pressure relief block is fixedly connected to one side of the fire hydrant, a pressure relief opening is formed in the surface of the side, away from the fire hydrant, of the pressure relief block, a pressure relief groove is formed in the end of the side, away from a constraint disc, of a pressure relief cylinder, and a plurality of pressure relief holes are symmetrically formed in the pressure relief groove. Two sliding grooves are symmetrically formed in the surface of the side, close to the pressure relief opening, of the pressure relief block, restraining mechanisms used for restraining the pressure relief cylinder are arranged in the two sliding grooves, a pressure gauge is installed on the side, away from the pressure relief block, of the fire hydrant, and a night pressure sensor is fixedly connected to the surface of the side, close to the fire hydrant, of the pressure gauge. The two sides of the pressure gauge are both fixedly co