The temperature field of fractured rock mass is one of the important researches in the multi-field couplings. It is also one of the hot and difficult problems at home and abroad. Based on the heat conduction equation, considering the heat exchange of rock and fissure water, the paper built the mathematical model of temperature field and used finite element method to conduct numerical solution. The result shows that when there is temperature difference between rock and water, there exists heat transmission,and the temperature will keep a value between them. Finally, the model can settle certain foundation for multi-field couplings of fractured rock mass.