Our country has always attached great importance to the construction of urban sewage pipe networks, with coverage rates similar to those in Europe and America. However, most rivers in our cities are severely polluted. The main causes include damaged drainage pipes, mixed connections, and widespread overflow issues. Pipe network problems have become a 'bottleneck' issue in the battle against urban river pollution control in our country. Independent innovation in developing key technologies is crucial and of profound significance. With continuous support from national science and technology projects, the project team has spent over a decade breaking through technical bottlenecks and innovating a key technology system for the treatment of urban river pollution with high pipe network coverage rates, which has been widely promoted and applied. The first innovation is the establishment of a non-excavation numerical diagnosis method for pipe network problems, and the innovation of non-excavation repair technology for damaged pipes, solving the difficult problem of low sewage interception efficiency. To address the issue of cities in our country being unable to fully excavate for network pipe diagnosis and repair, an array analysis was established to express the characteristics of water quality from different sources. The Monte Carlo method was applied to calculate characteristic water volumes, and zoning inversion was used to accurately diagnose damage. This approach achieved precise identification of mixed connection points and was applied to the diagnosis of some city networks, revealing that China's network problems are severe, with a high rate of mixed connections and damage exceeding 30%. To this end, innovative non-excavation construction methods for inner lining hoses were developed, including robots with pipeline flushing functions, a multi-level hydraulic repair construction integrated work platform, and cylinder-adjustable multifunctional jigs to enhance the quality and timeliness of inner lining repair construction. These innovations were applied to the non-excavation repair of networks in 16 cities, effectively solving the problem of network damage. Innovation Point Two: For the first time, research on an automatic sediment flushing device for network pipes was developed, innovating and strengthening cyclone separation technology to solve the difficult problem of controlling network sediment pollution. Through the analysis of the multiple source pollution balance relationship of the network, It has been determined that about 60% of the pollution load discharged by the rainwater pipe network comes from sedimentary pollution. To address this, in-situ identification sensors were developed to analyze the impact of microbial secreted viscous substances on shear performance in pipe network sediments. Hydraulic automatic flushing devices were also created, achieving a flushing efficiency of over 60% on sunny days. For sudden discharge during rainy periods, an innovative short-term flocculation enhancement technology was developed in a high turbulence field with cyclone shear, where the effective particle size increased to more than 100μm, and the removal rates for COD and SS exceeded The project revealed that overflowing sewage is the main cause of black and smelly urban river channels during rainy days, and clarified that the proportion of mixed sewage connections and the number of sunny days in the early stage are the main influencing factors. A full process analysis model for rainfall-runoff-overflow was developed, establishing a new method for designing retention ponds to control overflow concentration. This method was applied in cities such as Hefei and Fuzhou, solving the difficult problem of quantitative analysis of retention pond volume based on river water quality protection. A technology for generating 100-200nm nano bubbles through hydraulic cavitation forced bursting was developed, which increased the oxygen mass transfer rate by 10-100 times compared to ordinary bubbles, effectively addressing the anaerobic problems caused by overflowing sewage. It played an important role in the treatment of more than 30 black and smelly water bodies. The results were applied in comprehensive pollution control projects for over 60 heavily polluted rivers in 19 provinces (cities) including Shanghai and Guangdong, with significant improvements in water quality. The project led or participated in the compilation of 11 technical standards and specifications, authorized 26 patents (including 11 invention patents), Software copyright 12 items; Invited to compile a thematic technical report for the United Nations Human Settlements Programme, which was highly praised by the Deputy Secretary-General of the United Nations, Sharif, as providing successful lessons for developing countries. The report was released at the fourth session of the United Nations Environment Assembly and promoted at the first session of the United Nations Habitat Conference. Research results were published in Nature Sustainability, with 101 SCI and EI papers, and six monographs edited or co-edited, resulting in significant socio-environmental benefits.