Steel truss bridge suffers heavy wind in open sea. The wind load even plays a crucial role on the bridge. It has two different calculation methods for the wind load in accordance with two different codes General Code for Design of Highway Bridges and Culverts and Load Code for Harbor Engineering. The article is to calculate and analyze the cause of the difference by two codes on the basis of a 90 m long steel truss bridge in a wharf project, and give suggestions on the future design.