In the design of road reconstruction and extension projects, various complex traffic nodes are often encountered. Taking the expressway project of Longdong Avenue as an example, the issues related to the affected areas of the subway in the project are listed. Through the analysis of the design difficulties of complex nodes, combined with the conventional technical parameters of rail transit line planning and control, and the impact of elevated bridge structure pile foundation on the subway planning line position, and aiming at the complex traffic nodes, the multi-round optimization and negotiation are carried out for the design scheme. Finally, a scientific and reasonable technical solution is proposed, which provides the effective reference for the design of similar complex traffic node in the future.