Load test device of casing hanger

The invention discloses a load test device of a casing hanger, the casing hanger is provided with a mounting through hole, a seat ring bearing step and a bearing end face, a hanging internal thread is arranged in the mounting through hole, the load test device of the casing hanger comprises a body, a test cavity is arranged in the body to accommodate the casing hanger; the pressure head body is movably arranged in the test cavity and is provided with an abutting end and a connecting end, the abutting end is provided with an abutting face matched with the bearing end face, and the connecting end is arranged in the mounting through hole in a penetrating mode and has a connecting state and a separating state with the hanging internal thread; the bearing step structure is located on the side, away from the bearing end face, of the seating ring bearing step, and the seating ring bearing step can abut against the bearing step structure in the axial direction of the casing hanger; when the connecting end and the han