Objectives: The Guanzhou Waterway in the lower Yangtze River, a typical goose-head-shaped braided channel, has long been characterized by complex evolutions of shoals, braided channels, and water-sediment diversion patterns. Existing studies mainly relied on data prior to 2016, failing to address the long-term impacts of new flow-sediment conditions (e.g., clear water discharge from upstream reservoirs) and the efficacy of revetment projects implemented since the 1960s. This study aims to: 1) analyze the recent riverbed evolution characteristics (2003-2023) from multiple dimensions (boundary conditions, diversion ratios, shoal dynamics, thalweg shifts, and erosion-deposition changes); 2) quantify the influences of revetment engineering, upstream reservoir impoundment, and downstream confluence processes; 3) predict future evolution trends; and 4) propose targeted control measures for river regime stability. The research innovatively integrates long-term field observations (1966-2023) and systematic analysis to bridge the knowledge gap in braided channel management under human interventions. Methods: Long-term hydro-morphological datasets were employed, including: (1) Topographic surveys: 1:10,000 scale maps from 1966, 1977, 1987, 1998, 2003, 2012, and 2023, focusing on changes in shoal areas (e.g., Qingjie Shoal, Fusheng Shoal), thalweg positions, and cross-sectional parameters (width, depth, width-depth ratio). (2) Hydrological data: Annual runoff and sediment discharge at Datong Station (1966-2022) to characterize flow-sediment regime shifts, particularly post-Three Gorges Reservoir impoundment (2003).(3)Engineering records: Historical revetment projects (e.g., San yi Wei, Guanzhou Shoal) were mapped to assess their impacts on channel boundary stability.Quantitative analyses included: 1) statistical comparisons of diversion ratios among branches (Dongjiang, Xinzhong Branch, Nan jia jiang); 2) erosion-deposition calculations (volume changes in riverbed below +5m elevation); and 3) trend analysis of key sections (GZ2#, GZ7#, GZ19#) to identify dominant evolution patterns. Results: (1) River Regime Stability Under Revetment Engineering: 1) The overall river regime has stabilized since the 1980s due to continuous revetment works, which constrained lateral erosion of the left bank and fixed the main channel of Dongjiang. The width-depth ratio of key section GZ7# decreased from 1.45 (1998) to 1.28 (2023), indicating a narrowing and deepening trend, which stabilizes the main channel. 2) The Xinzhong Branch, once a thriving secondary channel, has become nearly inactive with a dry-season diversion ratio dropping to 1% (2023) due to sedimentation at its entrance and reduced hydrodynamic forces after the collapse of Guanzhou Shoal’s tail. (2) Impacts of Clear Water Discharge:1)Post-2003, the annual sediment load at Datong Station decreased by 68.5%, leading to overall riverbed erosion. The channel volume below +5m elevation increased by ~6% (2003-2023), with severe erosion in the confluence section’s left bank and the head of Qingjie Shoal.2)The Nan jia jiang Branch showed a gradual increase in diversion ratio (from 15% in the 1980s to 24% in 2023) due to scouring at the left margin of Fusheng Shoal, but its development is limited by the single-node control of Huangshi Ji and weak downstream hydrodynamics. (3) Critical Evolution Trends: 1) Dongjiang’s dominance: Stable inflow conditions from the upstream Dongliu Waterway (after navigation regulation projects) and sedimentation in secondary branches ensure Dongjiang’s persistent role as the main channel. 2) Long-term erosion risks: The left bank shoal in the confluence section will continue to erode, potentially threatening downstream river regime stability. Scouring at the right margin of Qingjie Shoal’s head may slightly alter the inflow pattern of Nan jia jiang. Conclusions: This study highlights the critical role of human interventions (revetment projects) in stabilizing a historically unstable goose-head braided channel, while revealing new challenges posed by clear water discharge (e.g., localized erosion). Key innovations include: (1) New flow-sediment regime effects: Identified that reduced sediment load accelerates erosion in unprotected areas (e.g., Qingjie Shoal’s head, confluence left bank) while stabilizing secondary branches through sedimentation. (2) Targeted control measures: Proposed prioritizing monitoring and protection of three critical zones: 1) Qingjie Shoal’s head: To manage scouring-induced changes in Nan jia jiang’s inflow. 2) Left margin of Fusheng Shoal: To mitigate enhanced deflection effects from Huangshi Ji due to shoal erosion. 3) Left bank of the confluence section: To prevent downstream channel instability caused by persistent scouring.