The channel layout is greatly affected by topographic and geologic conditions，tidal current，and surrounding environment. Taking a public waterway project as an example and adopting tidal current and sediment mathematical model tests and ships maneuvering tests，we demonstrate on the plan layout of a channel from aspects including the natural conditions of the project area，the relationship between the project and the environmental protection zone，and the mid-long-term development planning of the port，and determine the optimal axis plan. We also discuss the design innovations when determining the channel dimensions to provide technical reference for the layout of similar long-distance channel projects with many comprehensive constraints.