Abstract: In this paper, the particle size composition of the classified coarse tailings and the classified fine tailings were tested respectively, and according to the test results, it was proposed to add a certain proportion of fine tailings to the classified coarse tailings to improve the particle size distribution of the tails, thereby preparing a paste backfill. The optimal addition ratio is coarse tailings∶ fine tailings = 5∶5 to 6∶4; at the same time, the spread test, bleeding rate test and compressive test of backfill slurry were carried out, and according to the test results, combined with the mining production experience, the recommended filling process parameters are as follows: the filling concentration is 74% to 76%; the cement-sand ratio is 1∶4 to 1∶10, which ensures the safe and reliable transportation of the filling slurry, and optimizes the strength of the backfill stope. Finally, according to the above recommended backfill process parameters, the backfill process and system plan were determined. Production practice has proved that this plan can meet the needs of filling production, the backfill system is reliable, and the process parameters are stable. It dramatically improves the backfill quality, provides a safety guarantee for further mining, and realizes safe and efficient mining.