The invention provides a device facilitating achievement of clamping and positioning of various parts. The device can achieve automatic control easily, and fast switching and positioning locking between various to-be-machined parts can be performed conveniently. The production efficiency can be improved, the product quality can be improved, and the mechanism has the beneficial effects of being easy to operate, convenient to maintain, safe in production and the like and is broad in application prospect. The mechanism comprises a pin 1, a supporting ring 2, a hook 3, a pin body 4, springs 5, spring pre-tightening nuts 7, a jackscrew 8, a pin body locking bolt 9, a clamping fixture installing plate 10, a cylinder 11, a cylinder rod 12, a pin locking nut 13, a pin body fixing plate 14, a pin body fixing plate bolt 15, a cylinder pin 16, a supporting ring gland 17 and a connecting rod 18.