During the process of rock failure under load, the temperature field of the rock surface will change with the increase of stress. In the article, a true triaxial test was carried out on the intact red sandstone, and a uniaxial compression test on the fractured granite was carried out. During the test, an infrared thermal imager was used to monitor the rock surface throughout the entire process, aims to obtain the temperature value of the rock surface. Introduce temperature standard deviation index, the temperature standard deviation is used to reflect the change characteristics of the surface temperature field in the process of rock failure, and the study focuses on the abnormal change of the temperature standard deviation before the rock failure. It is discovered from the experimental study that: The temperature standard deviation will rise abnormally before rock failure; The temperature standard deviation sensitivity of fractured rocks is much higher than that of intact rocks; Compared with the abnormal turning change of the temperature curve, the abnormal temperature standard deviation appears earlier and the phenomenon is more obvious. Temperature standard deviation abnormal response as an early warning information of rock failure, provide theoretical reference for the study of rock failure warning information.