This study develops to a modified RESED3D model, a quasi-3D model based on a vertical-horizontal splitting (VHS) method capable of simulating bed-evolution and river bank erosion/ sliding. This study fur-ther examines the channel stability influenced by the migration process of a meandering channel. Through focuses are also given on investigating the sediment transport mechanism of compound cross sections through characteristics analysis and field investigation. Theoretical analysis on an application study is employed to annotate the guidelines for hydraulic en-gineers in their designing and planning. Suitable models for the channel migration behavior in complex field, based on our literature reviews, are not yet developed. Thus, this study develops the proposed modified RESED3D to tackle down the complex field problems. Moreover, this project also demonstrates several sand bank failure experiments. The RESED3D model is adopted to simulate bank failure times and locations with the experimental data. The proposed modified RESED3D model was applied to a specific reach in Youluo River. Simulation results include bend flow, lateral flow and complex field near spur dike. The outcome of this study on Youluo River River will be valuable for the future bank improvement projects.