Abstract: Cracks of different widths and depths are observed in the cemented backfill roof in Wushan Copper Mine resulted from gravity stress and blasting vibration. The stability of backfill is affected when the cracks reach a point. This paper uses ANSYS software and GeoStudio2007 SIGMA/W module to simulate the stress-strain in the roof fissure filling body. The stability classification of filling body's base plate is studied based on ANSYS and GeoStudio coupling. Corresponding suggestions are put forward according to different stability statuses.