Butterfly valve with valve plate protection function

The butterfly valve with the valve plate protection function comprises a valve body, a valve plate, a valve rod and a sealing seat, a fluid channel is arranged in the valve body, the sealing seat is fixedly installed in the fluid channel, the valve plate is installed on the sealing seat in a rotating mode, the valve rod is installed on the valve body in a rotating mode, and the valve plate is installed on the valve rod in a rotating mode. One end of the valve rod is fixedly connected with the valve plate, the other end of the valve rod penetrates out of the valve body, circular truncated cone bases are detachably installed on the two end faces of the valve plate, each circular truncated cone base is provided with a center hole, a buffer plate is slidably installed in the center hole in the radial direction, and an elastic piece is assembled between the buffer plate and the valve plate. A hand wheel is fixedly installed at the penetrating-out end of the valve rod, the circular truncated cone base is connected