Abstract: With the increase of mining depth，Xincheng Gold Mine has entered the stage of deep mining，and is gradually facing with the problem of high temperature stress.In this regard，an analysis of deep underground thermal environment was conducted，the main heat sources and the formation mechanism in the mining area were analyzed，environmental factors such as air temperature，humidity and wind speed of different mining depths of roadways were measured by means of Engineering Thermodynamics.The temperature of surrounding rock in different depths was determined by Deep Hole Measurement Method and the variation regularity of geothermal gradient was studied.Test results show that the air temperature and water temperature of the roadways increase with the increasing of mining depth，the relative humidity of main mining levels are above 80% RH，the temperature of underground constant temperature zone in the mine area is 23 ℃，the normal geothermal gradient is 0.018 ℃/m，and the radius of heat adjustment circle is 17~18 m，all these will provide basic data for the effective control of thermal environment conditions in underground workplaces and the prevention and treatment of thermal hazard.

Key words: Deep thermal environment, High temperature mine, Temperature measurement of rock, Heat hazard analysis