The optimization of stope structural parameters and stability analysis in phosphate mines are of great significance for ensuring safe and efficient mining production. This study, based on the Laoheba Phosphate Mine as the engineering background, conducts research on the optimization of stope structural parameters and compares the stability before and after optimization. First, an orthogonal experimental design was used to develop a multi-factor, multi-level combination scheme for stope length, stope width, and pillar width. Then, through numerical simulation, key indicators such as roof displacement, stress distribution, pillar stress state, and the proportion of the plastic zone were systematically analyzed. After comprehensive weighted evaluation, the optimal stope parameters were determined as follows: stope length of 25 m, stope width of 10 m, and pillar width of 8 m. Further numerical simulation compared the ultimate bearing capacity of pillars before and after optimization. The results show that the optimized parameters significantly reduced the proportion of the plastic zone in the pillars, enhanced their load-bearing capacity, and, due to the increased stope area, improved mining efficiency. This study can provide a theoretical basis and technical reference for stope structural design and stability control in similar mines.