Abstract: The sediment deposition, water erosion and bank collapse will have a great influence on the shape of Jiangxin island, the reclamation of tidal flat, the change of channel and the ecology of estuary. In this study, Yangzhong, the second large island of the Yangtze River is taken as the research object. The erosion and siltation along the river bank of Yangzhong during 1973 and 2017 and the bank collapse in 2017 are monitored by remote sensing images. Furthermore, the reasons of dynamics are discovered by combining multiple data. Results show that: (1) the erosion and siltation along the river bank of Yangzhong are divided into three stages and characteristic differences of different stages are obvious; (2) after position identification, the bank collapse of Yangzhong is located in the intersection of two ancient rivers. One of them is on the right side of Taiping Island, the other is nearby it and in the southwest to northeast direction; (3) There is no obvious relationships between bank collapse and water erosion. Blocked ancient river outlets generate water pressure and grooves in river bottom induce rotational water flow then carry off sediment. In addition, river discharge after flood season aggravates the water pressure and then results in bank collapse directly.