To solve the problem of rapid growth of ship flow and insufficient channel capacity in Xiaomiaohong Channel,which is navigable by tidal channel in the radial sandbar sea area of northern Jiangsu province,and then the compound channel design is studied.Combined with the water depth conditions and the surrounding wading structures,it is determined that the section type of the compound channel adopts“the middle main channel and the small ship channel on both sides”.According to the prediction results of ship flow and the needs of maritime departments,the comprehensive comparison and recommendation of the construction scale,plane layout and navigation mark distribution schemes of multiple complex channels are carried out.The research results can provide scientific reference for the construction of radial sandbar sea area and other similar compound channels.