To reduce the normal siltation amount of the Yangtze Estuary deep-water channel，the jetty heightening project in the southern groin field of the siltation reduction project of the Yangtze Estuary deep-water channel is carried out in two stages：the previous project and the perfect project. Based on the measured data before and after the siltation reduction project in the deep-water channel，the changes of water and sediment flux，sediment concentration，flow field，surrounding river regime and siltation reduction in the channel are comprehensively analyzed. The results show that：1）after the previous project of the siltation reduction project，the water and sediment flow over the southern groin field decreased significantly，the sediment concentration in the north channel decreased significantly，the lateral water and sediment transport in the south side of the channel was effectively suppressed，and the actual normal siltation amount decreased by about 17.4%. 2） After the perfect project of the siltation reduction project，the water and sediment flow over the southern groin field are basically blocked，the sediment concentration in the middle and lower parts of the north channel also decreases，the tidal current direction of the north channel becomes more smoother，and the normal siltation amount decreases by about 5.6%. 3）The project achieves the expected channel siltation reduction target，the engineering treatment scheme is reasonable，and the channel siltation reduction effect meets the expectation.