Abstract: To address the issues in traditional open-caisson construction methods, such as large land occupation, high environmental disturbance, low work efficiency, difficulty in controlling the sinking process, and posture control in soft soil urban areas, an active-controlled prefabricated and mechanized open-caisson construction method is proposed. This method integrates technologies such as underwater robot excavation, ground-propulsion system penetration, synchronous grouting, and prefabricated segment assembly, etc. and has developed a complete set of construction equipment. Based on indoor tests and on-site field tests, the automation and controllability of underwater excavation robots were verified. The technology was applied to an escape shaft project on Shanghai Metro Line 13.The measured verticality of the shaft wall was about 0.65‰, and the overall structural average ovality was 1.2‰,both of which exceeded acceptance standards.