The top of the fire signal butterfly valve is equipped with a valve opening and closing electrical signal device. When the valve is closed by mistake by 25% (1/4 of the full opening), the electrical signal decoration will output the signal of being closed by mistake to the fire control center. This signal valve can accurately display the opening and closing state of the valve, and can directly, clearly and reliably reflect the working state of the fire protection system, so it is widely and widely used in the fire protection system.