Taking the stope of a uranium mine as the research object, based on the characteristics of the ore body and existing engineering experience, the upward horizontal slicing mining method is selected. The mining scheme model with different stope structural parameters is established by using the numerical method of FLAC3D. Through the numerical simulation of the stope mining and backfilling process, the temporal and spatial evolution characteristics of the stope stress field, displacement field and plastic zone are analyzed. The stability of stope is studied. The results show that the horizontal stratified height of 2 m is safer and more stable than 4 m, especially in the early mining period. With the development of mining operations, the stress concentration area of the stope gradually expands, and there are obvious stress areas through the top and bottom of the mining area. With the progress of backfill, the distribution of compressive stress inside the backfill body is more uniform, showing a small compressive stress, and the stress change amplitude is not large in the later period. The displacement at the intersection of roadway and stope is the largest, and in the early stage of mining backfill operation, the growth rate is fast and the near-vertical jump growth occurs. The displacement changes at the middle part of roadway and the top plate in the middle part of stope show phased changes, and the overall displacement is small.