Abstract: In order to study the effect of shock load on the degradation of the mechanical properties of the traction transformer winding solid insulation materials, firstly, we designed a shock load test platform, and performed shock thermal aging tests at different temperatures, then, the tensile strength and degree of polymerization of samples were tested. Based on the test results, the effect of shock load on the mechanical properties of insulating paper was analyzed. Finally, a method for evaluating the life of insulating paper under shock load was proposed. The results show that the damage of the mechanical properties of the insulation caused by the traction load is mainly reflected in the extremely uneven temperature rise caused by the frequent shock of the traction load. The tensile strength and the degree of polymerization of the insulating paper will decrease as the shock time with the periodic thermal shock increases. The law is consistent with the law of thermal aging, but the rate of decrease in tensile strength and degree of polymerization under shock thermal aging is slower than that of thermal aging. The "induction" phenomenon occurs at a certain time in the tensile strength at a lower shock aging temperature, that is, the tensile strength is greater than that with a short shock time, and the critical temperature of the induced phenomenon is in the range of 90 ℃~100 ℃. In the study temperature range, the effect of periodic shock on the degradation rate of cellulose was taken into consideration, so that a method for evaluating the life of insulating paper under shock load was proposed, and the relationship between tensile strength and shock time was established, providing a basis for subsequent related research and engineering applications.