Abstract: Due to the large size of the transformer core vacuum annealing furnace, temperature distribution unevenness easily occurs during the annealing process, and the traditional thermocouple temperature measurement has the limitation of being unable to measure the internal workpiece. The COMSOL Multiphysics6.2 system was used to construct a simulation model of the transformer core vacuum annealing furnace, performing numerical simulation of the transient temperature field of the core workpiece. The model's accuracy was validated by comparing it with experimental measurement data. Temperature distribution was visualized through temperature contour maps, and the temperature conditions of the workpiece were analyzed. The coefficient of variation for the workpiece was calculated as 0.5741%. The uniformity of the temperature field was then optimized. The effect of the spacing between heating elements on the performance indicator was studied. The results show that, when the spacing between nichrome strips is 30 mm and the number is 20, the coefficient of variation for the workpiece is minimized. In terms of the heating process, when the first preheating temperature is 400 ℃ with a holding time of 60 min, and the second preheating temperature is 500 ℃ with a holding time of 60 min, the overall maximum temperature difference in the workpiece is reduced by 56.083 ℃