Abstract: To study the mining-induced damage characteristics of floor by paste filling mining on confined water, taking the stope conditions at 11607 working face of Daizhuang Coal Mine as engineering background, based on the numerical simulation software FLAC^3D, the fluid-solid interaction numerical model of confined water paste filling mining is established, the floor damage characteristics in the process of filling mining face in coal seam are analyzed. Research has shown that the progressive intrusion height of confined water of mining-induced floor by filling mining is not obvious, the damage depth of coal seam floor tends to smooth after the working face advances to 12.4 m, and when the working face advances to 100 m, the maximum damage depth is only 6 m. Theoretical calculation shows that the maximum damage depth of the mining floor in backfill working face is 3.83 to 5.27 m; using single-hole constant hydraulic pressure method to carry out field test on the floor of 11607 working face, the maximum damage depth of the floor is 6.50 m, which is basically consistent with the theoretical calculation and numerical simulation.