Abstract: Qinling railway tunnel is a long and deep-burying mountain tunnel with a length of 18 448 m and a maximum depth of 1.645 km. In this paper, considering the problems of high temperature that may probably exist in tunnel construction, the earth temperature field of the tunnel is simulated with FEM. The character of the earth temperature field is analyzed, and the temperature of the surrounding rocks of the tunnel is predicted. Base on the earth temperature, the tunnel is divided into five regions. Field measurement shows that the prediction method has a high practicability.