Abstract: Variation of internal infrared radiation temperature of composite coal-rock fractured under load was studied. The composite coal-rock is composed of top slate,coal seam and floor rock. According to the experiment,the sandstone sample and coal sample were drilled at their centerin different directions respectively. The internal temperature of the sample was measured by infrared thermometer to study the infrared thermometer variation characteristics in the process of the loading deformation until the hole was cracked. The results show that there are thermoelastic effect and frictional heat effect during loading tests. The heat generated by the friction between the coal body and the fracture surface is significantly higher than that of the thermal elastic effect,resulting in a significant increase of 0. 15 ℃ . The ther- moelastic effect of roof and floor sandstone plays a leading role,resulting in an increase of 0. 04 ℃ ,0. 05 ℃ respec- tively. The interior of the coal,roof and floor sandstone infrared radiation temperature and strain,stress and temperature all have a strong linear positive correlation.