Abstract: Based on the analysis of copper-nickel sulfide ore, the comparison of indexes before and after the application of middling separate regrinding and reseparation process, two grinding and two separation process, two grinding and two separation + middling regrinding process and the analysis of the process. Combined with the actual production situation on site, the paper analyzes the problems existing in the characteristics of the process. The analysis results show that, two grinding and two separation process in both the total nickel concentrate grade and recovery index were superior to the middling separate regrinding and reseparation process. The former general nickel concentrate grade of 7.96%, 0.26% higher than that of the latter, nickel recovery rate reached 83.65%, 0.25% higher than the latter. Two grinding and two separation process and two grinding and two separation + middling regrinding process shows that the latter can make low nickel concentrate grade is greatly ascend, rose from 3.95% before the implementation to 4.45% after implementation, at the same time the total nickel concentrate grade from 8.061% to 8.28%