Abstract: According to the difficult problem of rock burst in deep coal roadway, the display modes of coal impact failure, the function partitions of coal sidewall, the concatenation characteristics of micro cracks, and the main impact fractures were theoretically analyzed. The results show that the display modes of coal impact failure mainly have three forms, including plugging-sliding mode, slabbing-throwing type, crushing-ejecting type. Coal sidewall could concatenate the micro-fractures through horizontal, vertical and diagonal direction. The function partitions of coal sidewall mainly included peak stress area, friction limits area, compressed and ruptured zon, evaginated and weak area. The different concatenation modes of micro crack, the different interactive modes of four areas would form the different modes of rock burst. It was one of ways to control dynamic stability of coal sidewall by combining support pattern with pressure relief method and forming the support-depressurization cycle stripe of coal sidewall．