Method for checking contour precision of stamping die in numerical control machining

The invention discloses a method for checking the contour precision of a stamping die in numerical control machining. The method comprises the following steps: a hexahedral three-aperture hole gauge for detection is prepared, the hexahedral three-aperture hole gauge is placed in a stroke range of a large gantry type machining center, and the placement position is clean and flat; a main shaft of the large gantry type machining center is moved to the position right above the hexahedron three-aperture hole gauge, and the main shaft is wiped clean; a lever indicator is placed on a universal magnetometer base, and the universal magnetometer base is fixedly installed on the main shaft of the large gantry type machining center; a multi-section connecting rod of the universal magnetic magnetometerbase is manually adjusted to be vertical to a pointer of the lever indicator; the large gantry type machining center is controlled to drive the lever indicator to do circle drawing motion for zero clearing; and a contour det