Novel positioning device used in valve body type part trepanning procedure

A novel positioning device used in a valve body type part trepanning procedure is characterized in that four long-strip-shaped through holes are cut in a square transverse bottom plate, a square vertical side inserting plate is inserted into each of the left long-strip-shaped through hole and the right long-strip-shaped through hole, and a vertical V-shaped positioning inserting plate is inserted into each of the front long-strip-shaped through hole and the rear long-strip-shaped through hole; a material containing cavity is defined by the left square vertical side inserting plate, the right square vertical side inserting plate, the front vertical V-shaped positioning inserting plate and the rear vertical V-shaped positioning inserting plate, a valve part to be tapped can be placed in the material containing cavity, and the front end and the rear end of the valve part to be tapped can be clamped into V-shaped positioning grooves of the front vertical V-shaped positioning inserting plate and the rear vertical