The utility model is applicable to the field of valves and provides a self-sealing stop valve. The self-sealing stop valve comprises an integral valve body with a cavity. A sealing cover is detachably connected with a bottom end of the valve body, a sealing valve seat is arranged in the valve body, and a valve bar is penetratingly arranged in the cavity of the valve body. One end of the valve bar is provided with a valve clack matching with the sealing valve seat, and the other end of the valve bar is connected with a press component used for controlling opening or closing of the valve clack and the sealing valve seat. Two sides of the valve body are respectively provided with a medium inlet and a medium outlet communicated with the cavity, and a connection position of the medium inlet and the cavity is lower than a connection position of the medium outlet and the cavity. Sealing movement direction of the valve bar is the same to a sealing medium flow direction and a pressure direction, and the self-sealing stop valve is stable and reliable in sealing. Furthermore, the valve body with the cavity is integrally formed, the sealing cover is detachably connected with the valve body, assembling precision is lowered, and maintenance efficiency is improved.