Detecting dam leakage through the temperature field has a wide range of applications to practical works, and the theory using temperature field to solve seepage parameters is also developed rapidly. Scholars use temperature field to calculate seepage parameters. They assume that there are one or more leakage passages to establish a mathematical model which is used to calculate seepage velocity and seepage discharge. But this approach is only for dealing with problems of leakage channel, and this computation can’t be applied to all projects. Some of the scholars have established the mathematical models by using heat transport theory and percolation theory. However, those models are difficult to apply to solving all practical problems in engineering works because their boundary conditions are too ideal. Based on the summarization of previous findings, we have established a two-dimensional temperature model of the dam in semi-infinite space, and obtained the analytical expressions of the temperature in the initial boundary conditions in this study. At last, taking a reservoir project in Tibet as an example, the rationality of the application of this model to practical works is verified.