Self-locking device for fixedly connecting telescopic pipe fittings

The utility model discloses a self-locking device fixedly connected with a telescopic pipe fitting. The self-locking device comprises a sleeve, an insertion pipe, a clamp and an eccentric wheel locking handle, wherein a positioning groove is formed in an upper end opening of the sleeve in the axial direction of a wall body; a groove is formed in the outer circle wall face of the insertion pipe in the axial direction; a groove in the insertion pipe is a V-shaped groove, a V-shaped boss matched with the V-shaped groove is arranged on the inner circle wall face of the clamp, the V-shaped boss is connected with the inner circle wall face of the clamp through a guide piece, and the guide piece is clamped in a positioning groove of the sleeve. The V-shaped boss and the V-shaped groove which are used for limiting are matched in a limiting mode, so that the V-shaped boss and the V-shaped groove are more attached, and it can be guaranteed that the inserting pipe cannot rotate relative to the sleeve pipe. At least one