The invention relates to a comprehensive building of an urban water plant, which can save land occupation, reduce investment and operation expenses and facilitate management. An elevator and stairs are arranged at the two end parts of a comprehensive building body respectively, going to the underground garage through the middle floors from the top layer; a gate is arranged on the outer wall of a staircase hall; a family member courtyard terrace is arranged outside the gate; an overhead bridge of the water plant area road isolated from the family member courtyard terrace is arranged above the family member courtyard terrace; an isolation wall is arranged between the family member courtyard terrace and the water plant area terrace; facility stairs are led to the water plant area terrace from the facility layer; each soil stack of the high-rise residential building and the facility layer can discharge water to an outdoor drainage inspection well from the gathering soil stacks in pipe shafts at the two ends of the comprehensive building body respectively; isolation layer channels are arranged at the central part and isolated from each other; and water and gas supply pipelines, central heating pipelines and power supply, telephone and television lines are allocated to each user by the pipe shafts at the two ends of the building body. The comprehensive building provided by the invention has a unique structure and comprehensive functions, and is a great innovation of the water plant building.