Main valve protector of shale gas production wellhead

The invention relates to a main valve protector of a shale gas production wellhead. The main valve protector comprises a valve body. The main valve protector of a shale gas production wellhead also comprises a mandrel and a lower flange arranged under the mandrel. The lower end of the mandrel is arranged in the lower flange. The lower flange is fixedly connected with the valve body in a bolt connection method. The upper end of the mandrel is provided with an upper flange. The upper flange is provided with a plurality of positioning nuts. A displacement lead screw is arranged between the positioning nut and the lower flange. The inner wall of the lower flange is provided with a plurality of groups of sealing components. Through the mandrel passing through a valve element when fracturing occurs, a fracturing fluid is prevented from washing the valve element, so as to improve service life of a manual flat valve and realize to reduce development cost. The main valve protector is simple in structure, convenient in