Water pollution coming from mining CBM which is a major environmental issue can be classified as two types, fracturing return water and production discharge according to production time. Water volume and quality vary with location, generally showing a descending trend, with mineralization degree, COD, ammonia nitrogen, floats and fluorides as its chief indicators. In Chinas practice, water from CMB mining is discharged after settling down, but quality is much different from local standards, which shall be unified. Water shall be treated according to regional terrain, water quality and volume. This paper suggests applying natural evaporation, decentralized and centralized discharging based on allowable conditions. Besides removal of floats, ammonia nitrogen and COD, further processing needs to be done to treat fluorides, sulfides and iron ions. Treatments vary with mineralization degrees. Water after processed, if allowable, may be used for fracturing liquid, agricultural irrigation or sprinkling plants.