With the rapid development of urban construction in our country, the stability analysis of soft soil areas due to excavation for deep foundation pits and shield tunnels has become increasingly complex. The impact of underground engineering excavation on adjacent buildings, subway tunnels, underground pipelines, and other surrounding environments cannot be ignored; the instability issues caused by deep foundation pit excavation and shield tunnel crossing in high-pressure water-bearing sandy layers are also receiving significant attention. How to evaluate the stability of underground engineering excavation and its impact on the surrounding environment, and to propose corresponding control technologies based on the safety standards of the project itself and the environment, is one of the important technical challenges in current engineering construction. For the stability of underground engineering excavation in soft soil areas, especially the influence of high-pressure water-bearing sandy layers, which face many risks of instability disasters, but there is currently a lack of systematic stability analysis. For underground excavation projects in environments with dense buildings and lifeline engineering, Due to the sensitivity of the surrounding environment to deformation, the design and construction of underground engineering have moved from an era dominated by strength control to one focused on deformation control. Currently, the analysis of the impact of underground excavation on the surrounding environment is relatively backward and cannot meet the growing demands of engineering practice. Therefore, it is very necessary to form effective key technologies for the safety of underground construction and environmental impact control based on theoretical and experimental research results. This research group, supported by more than ten scientific research projects including the Shanghai Outstanding Academic Leader Program, Shanghai Key Science and Technology Project, National Natural Science Foundation, etc., has conducted in-depth and systematic research on the theory and control technology of stability and environmental impact analysis for soft soil underground engineering based on theoretical analysis, indoor tests, field measurements, and engineering practice. The following are the main innovative achievements: (1) A three-dimensional strength theory of soft soil considering the rotation of principal stress axes due to underground excavation has been established. A limit analysis method for the anti-bulging stability of layered K0 consolidated soft clay foundation pits and a three-dimensional analysis method for tunnel excavation face stability considering seepage effects have been proposed; (2) An analytical method based on inverse analysis that considers the small strain characteristics of the soil body for foundation pit excavation deformation analysis has been proposed, as well as a displacement control analysis method for the impact of tunnel excavation on adjacent pile raft foundations and underground pipelines in stratified foundations. An index for controlling ground engineering deformation based on the self-deformation bearing capacity of buildings (structures) has been established; (3) A systematic proposal for key construction techniques for controlling deformation of adjacent subway tunnels during deep foundation pit excavation and comprehensive management technology for the hazards of confined water has been made, as well as a comprehensive construction technique for environmental impact control of shield tunnel excavation in urban complex environments and safety control technology for high-pressure confined water sandy strata construction. The project research results have been successfully applied in the Shanghai Century Metropolis deep foundation pit project, the Shanghai Rail Transit Hanzhong Road Hub Line 13 station deep foundation pit project, the Shanghai Rail Transit Lines 9, 12, and 7 inter-station tunnel projects, as well as the Hangzhou Metro Line 1 Qiantang River Tunnel project and the Shanghai 'Tangdong Central Headquarters Base' deep foundation pit project. These applications effectively ensured the safety of soft soil underground engineering and environmental protection, achieving a direct economic benefit of 186.8 million yuan, resulting in significant social and economic benefits. The project research has promoted the development of theories and control technologies for the safety and environmental impact analysis of soft soil underground engineering. It has applied for 10 national patents, of which 7 have been authorized, published 98 papers, including 12 in SCI journals, 2 in SCI source journals, and 50 in EI journals; it has formed 1 Shanghai municipal-level construction method. The research results have been incorporated into relevant norms in Shanghai, making significant contributions to the advancement of industry technology and academic development. They also hold important promotional and application value in the field of soft soil underground engineering design and construction.