When a sudden short-circuit fault occurs, the current will surge instantaneously. The interaction between this high current and the magnetic flux leakage in the winding will produce huge electric force, which is easy to cause winding distortion, deformation and even fracture. If potential problems such as winding deformation are not found in time and continue to operate, the cumulative effect will gradually increase, seriously threatening the service life and reliability of power transformers. Based on Lemaitre damage model, a short-circuit impact simulation model including cumulative effect was constructed. The leakage magnetic field distribution around the winding during short circuit was calculated by finite element method. Combined with the multi physical field coupling of electromagnetic field and structural field, the stress distribution and deformation process of the winding under electrodynamic force were monitored, and the rule of cumulative effect on the stability of winding structure was analyzed. At the same time, a power system model with different short-circuit points was constructed to simulate various working conditions, and Lemaitre damage model was used to quantitatively analyze the impact of each short-circuit impact on the winding. Based on a large number of simulation data, L-N damage equation was proposed to describe the cumulative effect of winding short-circuit impact, which provides a scientific basis for transformer condition assessment and preventive maintenance.