Artificial freezing method has been widely used in various underground projects, but the development law of freezing temperature field of complex curtain is difficult to be calculated by analytical method. As a general method, numerical method is feasible to simulate the development law of horizontal freezing temperature field of complex curtain. In this paper, the development law of temperature field in the freezing process is analyzed based on the freezing method construction of a subway connecting passage. The feasibility of this method is verified by comparing with the measured data. The results can be used to guide the design and construction of artificial freezing.