This project falls within the field of urban and rural planning and construction. Megacities such as Shanghai are facing significant transformations in land use from incremental to stock, development models from outward expansion to inward enhancement, and urban construction from large-scale demolition and reconstruction to gradual renewal. How to achieve both the improvement of urban functions and environmental quality and ensure the continuity of urban style and spatial characteristics during the renewal process in complex environments of high-density existing urban areas has become a major challenge. The project took over ten years to develop, targeting the current characteristics of high complexity, high sensitivity, and multiple constraints in high-density existing urban areas. Relying on national and local major science and technology plans, through intensive collaboration between industry, academia, and research, a set of key technologies for organic urban renewal was established, which adheres to the principles of minimal intervention and refinement, covering the entire chain from information assistance to planning design and construction implementation. The innovative achievements of the project include: 1) Research and develop high-precision collection, intelligent management, and visualization assistance application technologies for environmental information to provide a digital foundation for urban renewal planning and construction: Adopting an integrated terrestrial and aerial multi-machine collaborative network, establish a high-density complex urban area three-dimensional model field with millimeter-level accuracy; Research and develop a dynamic monitoring and early warning platform for the health and safety status of existing buildings and infrastructure; Seamless and efficient integration of BIM and GIS technologies, construct a full lifecycle management system for urban three-dimensional model information, a mobile terminal-based virtual simulation scene dynamic implantation platform, interactive augmented reality, and other methods and technologies to optimize and enhance the decision-making and management efficiency of urban renewal planning and construction. 2) Propose an all-element refined planning technical method that integrates protection and renewal, pioneering the 'two plans in one' for protection and renewal, solving the difficult problem of guiding and controlling small and micro-scale urban renewal construction: For the first time, a unified indicator system has been implemented at the level of China's legally mandated control detailed planning to accommodate both technical indicators for updated construction guidance and key elements for urban protection guidance. A refined planning technical framework for the entire built environment has been proposed, creating a multi-department collaborative management technology platform, which solves the problem of traditional incremental urban planning techniques lacking guidance and control over small-scale dynamic updates. An automatic generation system from planning construction indicators to three-dimensional spatial models has been developed, providing effective technical means to regulate and balance the relationship between protection intensity and update intensity. 3) A refined construction technology for the built environment under multiple constraints has been created, minimizing the impact of updated construction activities on the existing urban spatial environment and daily operations: Construction techniques and equipment under high spatial constraints have been developed. The project has solved the problems of construction infeasibility or low efficiency in existing urban underground spaces and narrow spaces within buildings. It has developed comprehensive renovation and development construction technologies and equipment for the transformation of existing buildings, addressing the challenge of not shutting down commercial facilities during high-density urban renewal projects with large pedestrian flows. The project has also researched low-cost and high-efficiency environmental restoration technologies and equipment, solving the severe environmental pollution issue during the transformation of existing urban industrial land. The project has been authorized with 10 invention patents, 7 utility models, and 7 software copyrights. It has edited 1 national standard and 2 local standards. The project has published 6 monographs and 76 papers, with 2236 citations. The project's outcomes have been directly applied to the protection and renewal planning of 44 historical districts and more than 50 characteristic roads covering 41 square kilometers across Shanghai; the evaluation of the renewal planning for the Shanghai riverfront area along the Yangtze River (the Huangpu River) and Suzhou Creek; Shanghai No. 1 People's Hospital has undertaken multiple important demonstration projects such as the renovation of the comprehensive building and the renewal and transformation of the first eight-hundred-meter shopping mall. In recent three years, it has cumulatively generated direct economic benefits of 1.63 billion yuan. It has won 3 national urban and rural planning design awards, 5 Shanghai urban and rural planning design awards, 2 Shanghai decision-making consulting research achievement award winners, 1 National Excellent Surveying Engineering White Gold Award, and 1 Luban Award.