Many old mines had difficulties in upward mining caused by restrictions of production technology and  exploration capacity, unclear exploration of coal seam distribution and immature mining thin seam technology. In order to determine integrity and continuity of overlying No.2 coal seam after mining No.7 bottom coal seam to distinguish feasibility of upward mining, method of digging along No. 2 coal seam roadway was carried out. The results showed that goaf in No.7 coal seam had reached full state and No. 2 coal seam had been fully sunk; integrity and continuity of No. 2 coal seam were not damaged, which meant that upward mining in No. 2 coal seam was viable. The conclusions were consistent comparing with prior result of numerical simulation in underground.