Abstract: In order to improve the pretreatment capacity of mine water containing suspended solids andreduce the pollution and blockage on the subsequent membrane system,the operation problems existingin the mine water pretreatment systems of 9 typical coal mines in a mining area were analyzed,and theoptimization measures were put forward. The results showed that the treatment efficiency and effluentstability of the mine water pretreatment systems were improved through some measures such as processoptimization,structure transformation and improvement,equipment intelligent upgrade,and reagent opti-mization. The average removal ( %) of suspended solids in effluent was increased by 8% ~15%. Theoperating cost of the optimized pretreatment system was reduced to 0.2 ~0.4 yuan /t,which was 5% ~20% lower than that before optimization. The comprehensive operating cost was decreased by 3% ~25%. Close-