Abstract: It’s the first time in the research field of rock mechanics that the computerized tomography (CT) real-time testing of fatigue damage meso-propagation law of rock have been accomplished in this paper using the specified loading equipment of the CT machine developed by the authors. Through the meso-scale CT testing ,it was confirmed that the fatigue damage of rock has a threshold value.The law of fatigue damage of rock about the variation of cyclic loading maximum stress value was studied.The initial fatigue meso-damage propagation law is given.