The beneficiation process in a gold mine in Inner Mongolia is Nelson (table) gravity separation＋flotation process,and the gravity separation doesn’t have desirable gold recovery outcome.In order to explore the cause and solution,the grinding classification system and gravity separation system are investigated on their process flow.The results show that the gold accumulation phenomenon taking place in ball mills and pump sump is the main factor that influences Nelson gravity separation recovery rate,and short stable operation time of Nelson separator will also impose influence on the gold recovery rate;steel ball filling rate is low and grinding efficiency is poor for the ball mills in the grinding classification system;optimization suggestions are put forward according to the problems found in the flow,providing basis for next-step improvement of gravity separation recovery rate and optimization of grinding classification system.