The study on the failure mechanism of rock only by one test method usually is lacking in contrast.The uniaxial compression tests of coal-rock and granite were carried out,at the same time,the test of infrared imaging and acoustic emission motioning were made on the samples.The complete stress-strain curves of the samples were obtained by the uniaxial compression tests,and the infrared images and acoustic emission signals were analyzed.The results of comprehensive analysis show that the process of rock failure is a process of energy transformation in fact,the failure mechanism of rock is not same in the different phase of fracture,the interior stress field of rock is very complex under uniaxial compression condition,the rock failure is a process of evolution from local crack to whole fracture.