Power transformers, as key equipment for energy transmission and conversion in the power grid, are inevitably subjected to short-circuit current impact during operation. The transformer’s ability to withstand short-circuit current impact directly affects its own safety factor and the sustainability of the entire power supply network. During the operation of the transformer, as the running time increases, the temperature of the transformer winding and insulating components also changes with the increase of running time, and the mechanical properties also change accordingly, thereby affecting the transformer’s short-circuit mechanical cumulative effect. By studying the mechanical cumulative effect of the transformer under different temperature conditions, it is possible to calculate the transformer’s mechanical performance more accurately in actual operation, thus improving the scientificity and accuracy of transformer design. This study changes the dynamic mechanical experiment of the transformer's insulating components under different temperatures, and obtains the dynamic cumulative curve of the transformer’s insulating pad blocks at different temperatures. The dynamic cumulative curve measured by experiment is input into the simulation calculation to calculate the cumulative displacement of the winding under the influence of different temperature insulating pad blocks. This paper uses a pressure machine to test the dynamic mechanical properties of insulating pad blocks at different temperatures, and the experimental results show that as the temperature rises, the elastic modulus of the transformer’s insulating pad blocks gradually decreases. The dynamic curve obtained from the test is input into the two-dimensional refined model of the transformer for calculation, and the simulation calculation shows that when the temperature of the transformer’s insulating pad blocks is high, the cumulative displacement of the transformer winding gradually increases, and the support performance of the conductor is reduced, thereby reducing the mechanical performance of the transformer winding. Therefore, studying the mechanical cumulative effect of transformers under multiple short-circuit conditions is crucial for ensuring the safe and stable operation of the power grid.