An efficiency promotion method of main coal flow key process in coal mine is proposed to solve the problem of low efficiency and production imbalance in X coal mine. Teamwork graph is used to find ways to eliminate the bottleneck based on the causes of the bottleneck of the main coal flow system. Serial work is done concurrently and the motions of workers are simplified following economic motion principle. And the frequency of the replacement of workers is adjusted. Finally, working time of each cycle is shortened by 15.82s, which increases the balance rate by 9.52%. Meanwhile, circle time is reduced by 24.06% and daily output is increased by 982.13t. The results show the feasibility and effectiveness of the method.