Aiming at the technical challenges faced in the expansion and upgrading of navigation-obstructing dam locks during the capacity enhancement of China’s inland waterways,taking the renovation project of the Yanzhou Hydro-junction on the Lishui River as the research object,systematic research is conducted on key technologies such as optimization of the overall hub layout,arrangement of an unprotected approach channel,determination of the minimum navigable water level at the final cascade,innovative shared layout of power plant and lock structures,application of high-performance materials,and construction diversion in narrow riverbeds.Through methods such as hydraulic model tests and analysis of measured hydrological data,a new hub layout scheme is proposed,which adjusted the original Z-shaped dam alignment to a straight-line alignment,increasing the navigable flow discharge from the original 7,000 m3/s to the 2-year recurrence interval flood standard of 8,910 m3/s.Innovatively adopting a shared structure for the ship lock and power plant building,saving a width of 20 m.Ultra-high performance concrete(UHPC)is applied in the bridge pier structures within the stilling basin of the sluice gate,which has three times the abrasion resistance of ordinary concrete.The staged diversion method combining precast concrete enclosure cofferdams with curtain grouting is applied in the ship lock project,successfully overcoming the construction challenges of highly permeable gravel bedding in a narrow riverbed.The conclusions indicate that this project has achieved multi-objective coordination including navigation safety,hub operation,flood control scheduling,and ecological environmental protection,providing a quantifiable and promotable technical path and engineering example for similar renovation projects of navigation-obstructing locks.