In response to the engineering problem of accumulated damage to roadways or stopes under under‑ground cyclic blasting disturbances, this paper comprehensively applies rock mass acoustic emission testing technologyand Flac3D numerical simulation to analyze the stability of the Yinshan Mine stopes. By analyzing the fatigue damagemechanism of materials and the principle of rock mass acoustic emission detection, a classification method for the integrityof rock mass in the stopes and a method for distinguishing cumulative damage are established. Then, based on theacoustic emission test results from multiple stopes on‑site, the stability of the backfill is characterized according to theintegrity and cumulative damage of the rock mass before and after blasting. By establishing a Flac3D stope excavationmodel, the stability of the stopes is further evaluated and analyzed. The acoustic emission detection results show thatbefore blasting, the rock mass is mostly at Level Ⅲ, and after blasting, the integrity of the adjacent rock mass is severelydamaged, mostly reduced to Level Ⅳ or Ⅴ. The numerical simulation results show that the stress in the model increaseswith depth, reaching the maximum at the bottom. The stress safety factor at the corner areas of the front, middle, andrear zones of the stopes is low, indicating instability. After the mining in the front area of the stopes, the pressure stressconcentration at the interface between the backfill and the rock is unstable, and after the mining in the rear area, theroof and backfill are mainly subject to compressive swelling failure. The research results provide a scientific basis foroptimizing the blasting plan and strengthening support measures in the mine, which is of great significance for ensuringthe safety and production of the mine and improving economic benefits. It also provides references for blasting opera‑tions in similar mines.