To further investigate the impacts of the Liuzihe comprehensive wharf project on the flow-sediment characteristics and riverbed stability of the Gong'an Reach in the mainstream of the Yangtze River,fixed-bed and movable-bed physical model tests based on measured topographic data from 2021 are carried out.Combined with prototype observations and 10-year flow and sediment data from 2013 to 2020,the 10-year riverbed evolution process after project construction is simulated,and the variations in flow field,water level,flow division ratio,and riverbed erosion-deposition evolution after project implementation are systematically analyzed.The results show that the overall impact of project construction on the river regime is weak,with the influence scope limited to 5 km upstream and downstream of the project area.The water level variation is less than 0.03 m,and the near-bank flow velocity adjustments are no more than 0.04 m/s.The flow division ratio of the Liuzihe anabranch increases slightly only when the discharge exceeds 22,000-24,000 m3/s,with a maximum increase of 0.10%.In terms of riverbed erosion and siltation,the inlet section presents the most significant siltation;the main navigation channel dredging area exhibits a periodic “siltation-rebalancing” process with a cycle of approximately three years;the harbor basin suffers obvious cumulative siltation with a siltation thickness of 2.0-2.3 m over the 10-year period.The project does not alter the overall river regime,and the 3.8 m deep navigation channel remains stable.This study reveals two local erosion-deposition evolution modes in the project area and proposes targeted strategies,including phased dredging,dynamic monitoring and long-term maintenance.