The design of approach channel is the important link for harbor general layout design, and the line selection of channel is the key for harbor and channel design. Due to the specificity of the cargo, there is a strict requirement of safety assurance for LNG vessel entering or leaving the harbor. Combining with the actual project, this paper presents the design idea for the layout of approach channel of LNG harbor. Considering the plan constraint factors, it proposes the schemes of line selection of channel, comparison and selection of approach channel layout schemes, and determines the recommended scheme finally. The design method recommended may serve as reference for similar projects.