A generator-type pressure relief device includes: a housing; a propeller disposed in the housing; a shaft fixed to the center of rotation of the propeller; a generator unit that generates electricity by receiving rotational torque from the shaft; an electricity storage unit that stores electricity generated by the generator unit; an electronic brake operated by an electric signal supplied from the outside to suppress the axial rotation of the shaft; a control unit that sends an electric signal to the electronic brake to control the operation of the electronic brake; and a water pressure sensor provided in the water supply pipe or the water drainage pipe or the housing so as to transfer water pressure information on the water to the control unit, and which allows the control unit to control the electronic brake.