Abstract: Underground gangue backfilling not only uses the gangue produced by the mine,but also recovers some pressed coal,which is more suitable for mining under buildings.It is an important way to achieve green coal mining.In this paper,combining with roadway filled mining in a coal mine,using computer simulation technology,the coal pillar stability in roadway during the process of filling mining was studied and the reasonable coal pillar design width was selected.According to experimental results,the actual filling rate of roadway filled mining is about 80 percent.Aiming at a mining area,two kinds of programs including roadway filled mining and strip mining were predicted,and the roadway filled mining has good surface reducing-subsidence effectiveness.