Self-locking anti-loosening fastener

The invention relates to a self-locking anti-loosening fastener which is suitable for occasions where nut and bolt fastener products are used. It is known that loosening prevention of fasteners is a worldwide technical difficulty. Through self limiting, a locked part can be kept in a state that the locking part cannot be loosened. The product is mainly composed of a limiting nut, a limiting bolt and a limiting sleeve locking nut, and is characterized in that a limiting pin is machined at the front end of the limiting bolt, threads matched with the limiting bolt are machined on the inner side of one end of the limiting nut, a structure matched with the contact face between a limiting sleeve and the limiting pin is machined on the inner side of the other end of the limiting nut, and limitingsleeve locking threads and a structure of a limiting sleeve side wall gap are machined on the outer side. A structure of the limiting sleeve locking nut is further arranged on the other side. When the locked part is locked b