The invention provides a self-separating locking and releasing device. The self-separating locking and releasing device can be realized through a restraint relationship between internal parts and cansatisfy that rigid connection between spacecraft locked equipment and a spacecraft body under a condition without relative separating motion is completely released on special occasions. The self-separating locking and releasing device comprises a flange A, a flange B, a bolt releasing device, a connecting bolt, a locking nut, a bolt separating spring, a bolt separating spring press cover, a locking pin, a locking pin separating spring and a locking pin separating spring mounting cap. As the self-separating locking and releasing device adopts an axial connection and transverse releasing workingmodes and the pre-tightening load of the self-separating locking and releasing device is smaller, the impact load to the spacecraft equipment is relatively smaller when the self-separating locking and releasing device is released.