Abstract: An iron-zinc mine was originally mined by non-pillar sublevel caving method. The third phase of the project needs to be expanded，and its mining method needs to be determined. Combined with the geological conditions of the mine，three methods of non-pillar sublevel caving method，sublevel drilling stage open stoping with subsequent filling mining method and large-diameter deep hole stage ore removal with subsequent filling mining method are selected. By comparing and analyzing the advantages and disad⁃ vantages，technical and economic indicators of the three mining schemes，the sublevel drilling stage open stoping with subsequent filling mining method and the non-pillar sublevel caving method are optimized. The optimized schemes are compared and demonstrated from the three dimensions of safety，production connec⁃ tion，ecology and social benefits. The research results show that the remaining production years of the mine are limited，and the ore body is pinched out downward. The use of the non-pillar sublevel caving method will not increase the range of the moving circle. On the contrary，the sublevel drilling stage open-stope sub⁃ sequent filling method is prone to the problem of one-step unroofing and two-step roof hanging collapse. In terms of production connection，the caving method can meet the production demand of 1.35 million t/a，and there is no production connection problem，while the sublevel drilling stage open field subsequent filling method needs to arrange three middle sections to meet the production demand，and it takes 3~4 years to reach the production. In terms of ecology，the caving method has little influence on the surface outside thecollapse pit and completes the corresponding reclamation，and the slope is monitored accordingly，while the mine filling method has the problem of water intake. In terms of social benefits，the net profit of the caving method is 151.186 1 million yuan more than that of the filling method. Finally，it is considered that the pil⁃ larless sublevel caving method is the best choice for the mine at this stage.

Key words: mining method optimization, non-pillar sublevel caving method, sublevel drilling stage open stoping with subsequent filling mining method, large-diameter deep hole stage ore removal with subse? quent filling mining method