Abstract: During the longwall top coal mining process, the top coal experienced two processes of cyclic loading and un-loading and stress rotation, respectively. In order to study the destructive effects of cyclic loading and unloading and stress rotation on the top coal, true triaxial mechanical experiments were carried out. The results show that the deformation and expansion characteristics of top coal under long-wall top coal mining are more complicated. The damage form of coal body is mainly shear damage, supplemented by tension damage. Under the main stress rotation path, the internal cracks of the coal body show the shape of "inverted Y". Under the graded cyclic loading and unloading path, the damage of the coal body is intense. Compared with the static load damage under conventional conditions, the longitudinal cracks caused by cyclic loading and unloading and the transverse cracks caused by stress rotation penetrate through each other, resulting in the crushing of the top coal.