Abstract: In recent years,with the rapid development of the Yangtze River Economic Belt,the waterborne transportation on the Yangtze River has become increasingly busy,and the vessel traffic density has significantly increased,The trend of vessel enlargement and specialization has become more and more obvious,which should be paid enough attention to. Accidents caused by the ship-to-ship effect often occur in the already narrow and complex navigation waters,The ship-to-ship effect occurs when vessels approach each other at close range,such as headon,overtaking or approaching a moored vessel,The symmetry of water flow on both sides of the vessel is destroyed,resulting in mutual attraction,repulsion,and oscillation,This phenomenon is especially noticeable in narrow waters,This study aims to conduct a grid overlap simulation analysis based on existing theories using the ANSYS simulation software,and use the Space Claim modeling software to model the vessel,As an example,the three-dimensional model created by Space Claim is imported into Design modeler for processing,In the simulation experiment,the method of controlling variables is adopted,with all other variables being fixed except the dependent variable,The differences in ship-to-ship effect under different vessel lengths,drafts,cross-sectional areas,and speeds are discussed,providing reference for vessel navigation overtaking on the Yangtze River.