The water ecological environment quality in cities and towns has been greatly improved by the reform of diversion system and the treatment of black and smelly water bodies, and the overflow pollution of confluence system has become one of the important problems of urban water pollution. Confluence system is studied in the overflow pollution control technology in the related literature, analyses the origin, characteristics, harm of the runoff pollution, from the source reduction, process control, end governance in three aspects, such as sponge city measures are put forward, embezzle to regulate, rapid sedimentation tank, engineering measures, such as artificial wetland and non-engineering measures such as strengthening management, system management. The future research direction is also prospected to provide reference for the design of sewage overflow pollution control in combined drainage system.