Yongdingzhuang Mining Industry No. 3 coal main belt down roadway is full seam roadway, roadway surrounding rock and coal seam roof and floor are typical soft rock. Based on surrounding rock feature, 4 observation station were settled in roadway, roadway roof and two sides displacement changes, the result showed that surrounding rock of observation station was stable, roadway floor affected by rheological surrounding rock pressure under two sides rock pillar and large deformation by its inflation pressure, drummed up to free face at a certain rate, floor rock lithology affected by water conditioning, with small softening coefficient, strong effect of deformation time and long time of deformation, corresponded to soft rock deformation mechanism.