Sealing gate valve capable of preventing leakage

The sealing gate valve comprises a valve body, a valve cover, a valve rod and a hand wheel, the valve cover is arranged at the top end of the valve body, a protective frame is fixedly arranged on the outer side wall of the valve cover, a heating pipe is arranged on the inner side wall of the protective frame, and fans are arranged on the inner top wall and the inner bottom wall of the protective frame in a vertically symmetrical mode. The bottom end of the valve plate is in closer contact with the groove through the groove, medium loss is avoided, the valve plate is clamped into the groove, the stabilizing effect of the valve plate is better, medium loss at the position of the valve rod is avoided through matching of the sealing seat and the sealing block, the heating pipe is heated by electrifying the heating pipe, and therefore the stability of the valve plate is improved. And then the fan is started to enable hot air emitted by the heating pipe to be dispersed in the protection frame, so that the valve rod