Abstract: The two-way coupling phenomenon between electromagnetic force and winding displacement exists during winding vibration. In this article, firstly, the axial vibration calculation models considering the two-way coupling phenomenon and one-way coupling phenomenon of the magnetic-structure field are presented, respectively. Secondly, the axial instability accidents of the transformer winding are analyzed, based on which the characteristic parameters affecting the winding instability during the axial vibration process are given, and the changes of these vibration parameters are used as the evaluation indexes of the two-way coupling effect. Finally, a 110 kV transformer is taken as the research object. The vibration process of the transformer winding with and without considering the two-way coupling effect is calculated by two methods, and the maximum value variation curves of the vibration parameters of each disk are obtained. The results show that, due to the two-way coupling phenomenon, the vibration intensity of the disks increases by 1.1~1.55 times, and the maximum electromagnetic force of the middle disk increases by 3.5 times. The appearance time of the maximum electromagnetic force of the middle disk is not at the first peak, but will move to the second or third peak. Hence, consideration of the two-way magnetic-structural coupling phenomenon is effective in analyzing the winding vibration process and can avoid the missed identification of weak points. The research results in this article can provide a reference for dynamic consideration of power transformer short-circuit strength.