Based on the data of normal siltation，hydrology，sediment，and topography in the 12.5 m deep-water channel of the Yangtze Estuary from 2010 to 2018，this paper analyzes the siltation changes and influencing factors of the channel. The results show that：1） The normal siltation volume of the Yangtze Estuary is large and fluctuates every year. The average annual normal siltation volume is about 65 million m3. In addition，the volume gradually decreases after 2012 and is currently stable at about 50 million m3，with an annual siltation intensity of about 1.3 m/a；2） Siltation volume and intensity show obvious spatial and temporal distribution characteristics，which are reflected by uneven distribution in flood and dry seasons and massive siltation in the middle of the channel；3） Factors affecting the spatial and temporal distribution of channel siltation mainly include the sediment source and sediment transport intensity，structures of water，sediment，and salt，and sediment deposition conditions in flood and dry seasons，as well as structures of water，sediment，and salt and sediment exchange capacity of shoal and passage in the middle channel of the North Passage. Furthermore，the middle channel of the North Passage is mainly affected by the sediment over the south dike；4） The inter-annual siltation change generally shows a decreasing trend. Specifically，the south channel to the Yuanyuan shoal section is related to the decrease in altitude difference between the beach and passage and the reduction of upstream sediment transport volume. For the North Passage channel，the project of heightening the sediment barrier in the south dam field has effectively improved its water and sediment environment，and the siltation is reduced by 17.6%.