The invention relates to an overturn deforming type unilateral bolt fastener which is formed by a bolt, a jacking sleeve, an overturn deforming piece, a gasket and a nut. A bolt head and a bolt rod are in circular conical surface transition, threads are arranged at the tail of the bolt rod, and the overturn deforming piece is an annular part with certain plastic deformability. The overturn deforming piece, the jacking sleeve and the gasket are arranged on the bolt rod in a sleeved mode, and the nut is screwed at the tail of the bolt rod. In the mounting process, one side of the bolt head is stretched into a mounting hole, the operation of screwing the nut at the tail of the bolt rod is started after the bolt head reaches the inner side of the mounting hole, the nut is screwed in continually to push the jacking sleeve to move forward, the overturn deforming piece overturns in the same direction and has corresponding deformation under the dual action of the jacking sleeve and the circular conical surface of the bolt head, the effect of radial expansion is achieved, in this way, the overturn deforming piece is made to directly act on the inner side surface of the mounting hole, and the unilateral connection and fastening of a structural piece are achieved. According to the overturn deforming type unilateral bolt fastener, unilateral operation can be achieved, the connection and fastening of the structural piece can be completed, and good mechanical properties can be achieved.