The temperature field during solidification has an important influence on the microstructure and properties of the material. Due to the difference of heat convection in space and ground environment, natural convection driven by gravity plays an important role in heat transfer in ground environment. However, in space, the microgravity environment almost eliminates the influence of gravity-dominated natural convection, which will lead to certain differences in the heat transfer characteristics between space and ground, resulting in differences in the temperature field distribution in the material experimental furnace. As a result, the temperature field obtained on the ground is different from that in space under the same temperature control conditions, thus affecting the equivalence of experimental conditions between space and ground materials. The heat transfer characteristics obtained from ground experiments cannot be directly applied to space experiments. This mismatch has a major impact on the space materials experiments. In order to obtain the heat transfer characteristics under microgravity conditions, a three-dimensional numerical model of heat transfer in the high temperature material experimental rack of the space station is established. In the modeling process, reasonable simplification is carried out according to the actual physical conditions, some minor heat transfer factors which have little influence on the overall temperature field are ignored. The temperature field simulation of the ground experiment and the space experiment was carried out respectively, and the temperature distribution of the sample box was obtained. The temperature obtained by simulation was compared with the measured temperature. Through comprehensive analysis of the changes of heat transfer parameters in the space microgravity environment and the normal gravity environment on the ground, the heat transfer law similar to the space condition was obtained. The research results provide a new way to predict the space temperature field distribution based on the ground experiment results of high temperature materials experiment rack and have important guiding significance for the future research of space materials.