Abstract: The grinding and classification system at a gold mine was optimized using JKSimMet software in order to increase the throughput and reduce the energy consumption of the concentrator. The optimization measures taken include reducing the feed size of the grinding circuit, adjusting the key process parameters of the ball mill and cyclone, and increasing the proportion from the coarse grinding circuit to the regrinding mill. The simulation results showed that some indicators had been improved after optimization. The processing capacity of the grinding classification system was increased from 35 t/h to 44 t/h. The specific energy consumption of the coarse grinding circuit reduced from 11.09 kWh/t to 9.94 kWh/t. The specific energy consumption of the middling regrinding circuit reduced from 9.93 kWh/t to 7.23 kWh/t, and the P₈₀ of the coarse grinding product reduced from 86 μm to 80 μm. The multi-objective optimization of the grinding products which included the improvement of processing capacity of the grinding classification system as well as the quality of the grinding products and the reduction of grinding specific energy consumption were achieved by the collaborative optimization of various process parameters of the entire grinding and the classification system.