PDCL-700 membrane residual chlorine is independently developed based on the technical route of laminated three-electrode method and combined with domestic water quality conditions. The electrode adopts optimized membrane process and sensing structure, and has good anti-surfactant interference ability. It has low pH dependence and is suitable for a variety of water environments, including tap water, agricultural drinking water, secondary water supply and other fields. The sensor responds quickly and the data output is stable, which not only ensures the accuracy and reliability of measurement, but also is more economical and convenient to maintain, which can meet the needs of continuous and accurate monitoring in different scenarios.