介绍了由Simatic S7-400 PLC、通用变频器MicroMaster和工控组态软件WinCC组成的基于ProfiBus-FMS总线的分布式控制系统及其在污水处理工厂中的应用。系统采用集中管理、分散控制的方式，上位机负责现场设备的远程控制和监视，控制站负责对具体的工艺、设备、主要被控参数进行控制及采集各种运行数据；上位机与PLC之间组网简单、运行速度快、通信稳定性强，系统提高了污水处理设备运行效率和管理水平，具有积极的推广应用价值。关键词：污水处理；溶解氧；分布式控制系统；ProfiBus；WinCCAbstract: The paper introduces a ProfiBus-FMS based distributed control system of sewage treatment, which is built with the inverter, S7-400 PLC and WinCC. The way of central monitoring management and dispersing control is used by the system: the long-distance control and monitoring of field equipment are uncharged of upper computer, the specific technology, equipment, the controlling of main parameter and several running data areuncharged of the PLC station. The net the between the upper computer and the PLC stations is simply building, quickly running and stable communication. The system has been successfully completed in sewage treatment, which has improved the operation efficiency and management level of sewage treatment equipment.Key words：sewage treatment; dissolved oxygen; distributed control system; ProfiBus；WinCC