Abstract: In response to the installation and use of electrolytic domestic sewage treatment equipment on the 115FPSO crude oil production facility of CNOOC Shenzhen Branch, serious scaling and difficulty in cleaning inside the electrode plate are prone to occur during use, resulting in a high failure rate of the electrode plate. This article designs an intelligent algorithm based system that can monitor the thickness of scale inside the electrode plate online and perform intelligent cyclic cleaning of the electrode plate. By analyzing the actual working conditions and operational needs of the offshore oil production facility No. 115, combined with the characteristics of electrolytic domestic sewage treatment technology, a human-machine interface system with the function of online monitoring of the internal thickness of electrode plates and issuing alarm prompt information has been developed, which can automatically cycle the cleaning device between electrode plates. The device has been successfully applied on site, achieving online monitoring of electrode plate thickness. When cleaning the electrode plate, the operation time has been shortened from 32 hours/time to 8 hours/time, the cleaning efficiency has been improved by 80%, and the energy consumption has been reduced by more than 60%, significantly improving the reliability of the sewage treatment system. Extend the service life of electrodes, reduce equipment failures, and lower equipment maintenance costs. The COD value of domestic sewage treated by the equipment decreased to 210 mg/L, which is lower than the national environmental protection standard for COD value of marine equipment domestic sewage.