Limin Mine 1603 fully mechanized mining face was taken as the study object, using similar simulation experiments predicted strata behavior, 1603 Initial Face weighting step was small, moderate-intensity pressure and the maximum pressure dynamic load factor of about 1.5 were predicted, the initial push could not adopt the weaken the roof measures. While, the causes and countermeasures of working face downpipe upward were analyzed, because of the inconsistency and down lane promote coal face angle change caused a tendency to change face length , which can be adjusted by circulating form of cutting knife, or disassemble the tail pushing the slide chute to free space, but cleaning the front frame float coal should be paid attention to.