Aimed at phenomena of support’s being pressed to burst or be unable to work in a few fully mechanized sublevel caving longwall faces

according to the analysis of the roof structures

their movement characteristics and the dynamic stability in fully-mechanized sublevel caving face

the mechanism of abnormal pressure on support in fully mechanized sublevel caving face is studied. The conclusion is that the main cause of abnormal pressure is sliding of roof structure. Because of the difference of sliding of roof structure

there are three of abnormal pressure. According to the analysis of the pressure on support

the computation formulae of abnormal pressure on support are presented. Using the dynamic stability judgement rules of roof structures

the types of abnormal pressure on support are distinguished and the computation means of abnormal pressure are defined; and the theoretical foundation about the selection of support in fully mechanized sublevel caving face and controlling abnormal pressure at field experiments are provided.