The key to safe, economical, and efficient production by the cut and fill stoping lies in selecting appro⁃priate backfill proportions mass ratios and stope structure parameters. With a mine using the delayed filling methodduring open stoping as the engineering background, Chinese and international research on backfill proportions andstope structure parameter optimization was investigated, and 4 types of fill mass with cement⁃sand ratios of 1∶4 and 1∶6and slurry concentrations of 68 % and 70 % were determined to meet the filling requirements through damage theoryand energy matching analysis between the backfill and rock mass. In view of costs, a cement⁃sand ratio of 1∶6 and aslurry concentration of 68 % were identified as the optimal ratio. On this basis, Flac3D software was used to numericallysimulate the selected stope structure parameters. Factors such as maximum principal stress, minimum principal stress,displacement, and plastic zone were analyzed. Four suitable stope structure parameter schemes were obtained: 44m（length）and 16 m（width）; 44 m（length）and 18 m（width）; 50 m（length）and 16 m（width）; 50 m（length）and18 m（width）. The scheme with the highest production capacity, i.e., a stope length of 50 m and a width of 18 m, wasselected as the optimal stope structure parameter for the mine. The research results will provide an effective referencefor subsequent mine production, helping the mine safely, efficiently, and economically recover ore resources. Mean⁃while, the research methodology and findings hold significant guiding value for similar mines.