Abstract: Underground coal gasification（UCG） is an environmentally friendly way to utilize coal resources, and its utilization efficiency depends on the characteristics of gas seepage in coal rock. Therefore, the permeability characteristics of coal rock under stress conditions are the key to the efficient implementation of UCG. The stress-related permeability characteristics of coal rocks in combustion zone（temperature above 500 ℃） have been extensively studied, while those in gasification zone（temperature below 500 ℃） have been less studied, but they significantly affect the gas flow efficiency from injection well to production well. In this study, the permeability evolution of coal rock with temperature（25-500 ℃） under different confining pressures is tested. The influence mechanism of temperature on the permeability of coal rock is studied based on the permeability model of coal rock. The main results show that: ① the permeability of coal rock decreases first and then increases with the increase of temperature. The permeability of coal rock increases significantly by 400% below 300 ℃, and decreases when it is above 300 ℃. ② The stress sensitivity of coal permeability decreases with increasing temperature. When the temperature is below 300 ℃, the reduction rate is 60%. ③ The permeability of coal rock samples has significant anisotropy, and the anisotropy increases with the increase of temperature. The permeability of horizontal 90° oriented coal rock is 4.56 times that of vertical coal rock, and increases to 6.14 times with the increase of temperature. ④ The average error between the permeability model and the experimental results is less than 4.3%. With the increase of temperature, the contribution of matrix expansion to the permeability of coal rock increases, while the contribution of thermal damage decreases. The research results of this paper clarify the permeability evolution characteristics of coal rock at the gasification front, which can provide guidance for the feasibility evaluation and process control of UCG.