The freezing temperature field of soil in the model tank is analyzed and simulated by Matlab PDE tool, and the accuracy of the simulated value is verified. Firstly, through the reasonable boundary assumption, the three-dimensional problem of frozen heat conduction of soil in model tank is transformed into two-dimensional space. Then, the Matlab PDE tool is used to simulate and compare the simulated temperature and measured temperature of the temperature measurement points. The results show that the heat conduction of soil in freezing temperature field can be simulated by Matlab PDE tool, and the operation is simple and easy to grasp. The accuracy of the simulated value of the temperature measuring point is related to the distance from the boundary and the freezing time.