Backfill mining method is an important construction method of mining. It is of great theoretical research and engineering practical significance to explore the strength characteristics of cemented tailings backfill after backfilling goaf. The influence of sand-cement ratio and confining pressure on the mechanical properties of uranium tailings cemented backfill was studied. Then, based on the three strength theories and the experimental data, the strength of cemented uranium tailings backfill with different sand-cement ratios was predicted. The results show that the sand-cement ratio has great influence on the mechanical properties of cemented tailings backfill. (1) When the sand-cement ratio is 4 and the confining pressure is less than 4MPa, the stress-strain curve of uranium tailings cemented backfill shows strain softening type, and the sand-cement ratio is greater than 4. The stress-strain curve of uranium tailings cemented backfill shows strain hardening type (2) Cohesion and internal friction Angle decrease with the increase of sand-cement ratio and gradually tend to be stable. (3) Rocker criterion formula is simple, which can accurately predict the strength of uranium tailings cemented backfill under different sand-cement ratios. Rocker strength criterion of uranium tailings cemented backfill considering sand-cement ratio is proposed, and its good prediction effect is verified. The above research will provide a useful reference for filling mining.