Abstract: In order to solve the rationality problems of hydraulic support selection in complicated structure coal seam mining process of Chenghe mining area,taking No.5208 fully-mechanized mining face as research background,through the method of field pressure observation and numerical simulation,the paper analyzes the mine pressure behavior laws and the evolution laws of development height of overburden fractured zone.The result provides scientific basis for reasonable selection of mechanized mining support in complicated structure coal seam of Chenghe mining area and efficient and safe production of the similar working face.