Forming method of non-standard nut

The non-standard nut forming method comprises the steps that a bolt is fixed to a first connected piece, and connecting threads of the bolt are located on the side close to a second connected piece; the bolt is stretched with theoretical axial pre-tightening force; axial section geometric parameters of the bolt at the connecting thread are obtained; determining thread geometric parameters of the non-standard nut according to the axial section geometric parameters of the connecting thread; and the non-standard nut is machined according to the geometric parameters of the threads. The non-standard nut is applied to thread fastening, the adverse effect of poor metric threaded connection stress distribution uniformity on the connection performance of the non-standard nut is improved, the phenomenon that a connection pair is prone to failure due to thread meshing force concentration in existing metric threaded connection is solved, the strength and the anti-fatigue performance of the connection pair are improved, a