Abstract: This paper analyzes the temperature field distribution characteristics inside a heat treatment furnace during heating via numerical simulation. A simplified model with 7-layer and 5-layer hollow partition structures is established. Taking the arrangement of electric heating elements and the effect of axial flow circulating fans into account, the formation mechanism of temperature gradient inside the furnace is revealed. The results show that obvious temperature stratification exists at the initial heating stage of the 7-layer partition structure. Vertically, the temperature is high at the top and low at the bottom with a temperature difference of 55 ℃; horizontally, it is high outside and low inside. The temperature stratification is gradually relieved after continuous heating. Comparative analysis indicates that the 5-layer hollow partition structure achieves remarkably better temperature uniformity than the 7-layer structure. Optimizing fan layout can effectively improve air flow distribution. The research results provide a theoretical basis for the optimization of heat treatment processes.