Abstract: To solve the problems of lack of agent adding capacity,shortage of quantitative adding device and low level of automation in tailing water agent adding system in Xinjulong coal preparation plant, taken the measures of improving the ability of adding system,perfecting the adding device and lifting the level of automation to reform the agent adding system. After the reformation,significantly improved the adding capacity and automation level,reduced the consumption of agent and the labor intensity of workers,increased the stability of the slurry treating system,and obtained better economic benefits.