Abstract: Infrared radiation tests of gneiss under uniaxial compression were performed to explore the infrared anomalies in the process of rock deformation and failure in different bedding directions.The evolution characteristics of infrared radiation temperature during the failure process were studied by evaluating factors including stress,average temperature,variance,differentiation rate of temperature field,and thermal image.The results showed that the evolution characteristics of the infrared radiation temperature field in different bedding gneiss loading processes have similar stages and changing trends.The linear fitting of average infrared radiation temperature and stress has a strong linear relationship.The temperature rise rate of the horizontal bedding specimen is higher than that of the vertical bedding specimen.The variance curve with stress can be divided into three stages.The compaction and elastic stage are small and change gently,and a greatly steep rise occurs during the failure stage.The abnormal characteristic points appearing in the middle and later stages of loading can be used as a precursor of rock instability.The variance is derived to obtain the temperature field differentiation rate.The point at which the temperature field differentiation rate shifts to the value of 0 for the first time and the point at which the value of offset to the value of imminent failure shifts to 0 are defined as the first and second warning signals,and it is concluded that time warning is better than stress warning.The infrared image is processed through a multi-step algorithm to reduce noise.The image quality is significantly enhanced.Near the macro-failure,the infrared thermal image has high-temperature radiation anomalies at the fracture position and low-temperature anomalies in other areas.This thermal image differentiation is an important infrared precursor characteristic of rock instability.