Abstract: Acording to the characters of the stractural geology, hydrogeology and geothermal geology in the coal-field in the northern of china, a method is proposed for predicting the rock temperature distribution in the coal mine field. That is the digital simulation method of the rock temperature field, which makes the result of the prediction more reliable, and simplifies the program of prediction. It is discussed in detail how to select the model and its boundary condition. Some examples on the hanging-wall block of the water-bearing fault are given to show the effect of digital simulation of the rock temperature（3 fig.）.