Abstract: In view of the quality differences between urban water and recharging water used as feed water of thermal power plants, the scaling and corrosion problems in the reuse process of urban water were analyzed. The depth treatments of lime method and membrane method for urban water and their application situationts in current coal-fired power plant are introduced, and their economical efficiency are analyzed. The results show that the applicability of the lime method is stronger; water quality obtained through the membrane treatment is good, but the operation maintenance workload is hard, the applicability of this method is relatively low.