The present application relates to the technical field of mechanical manufacturing, especially mounting seat hole closing tool, equipment and method, including the body, the front end of the body is provided with the front end tongue; When closing, the front end tongue cooperates with the U-shaped space between the part and the supporting mounting seat; The body is provided with a center; The end of the center close to the front end tongue is provided with a closing recess, the included angle between the groove wall of the closing recess and the horizontal direction is equal to the included angle between the side wall of the boss after closing and the horizontal direction, and the other end is provided with a jacking device. When closing, only the front end tongue is abutted against the inside of the U-shaped space between the part and the supporting mounting seat and the inner wall of the U-shaped space; The center is moved to the part direction to the outside wall of the boss and the side wall of the closing recess. The structure is simple, the operation is convenient, not only can realize accurate closing, but also can save a lot of manpower, improve the closing efficiency and closing quality. The problems of damaging the part, low closing efficiency and high cost in the prior art are solved.