The invention provides a manufacturing method for an aluminum alloy guide plate for a bridge. The manufacturing method comprises the following steps of: material selection; surface cleaning; cutting; shaping; welding; anodizing; surface coating and the like. According to the manufacturing method designed for the guide plate made of an aluminum alloy material, the guide plate is shaped many times in the manufacturing process so as to guarantee that the guide plate is not affected in quality due to deformation. By way of spot-welding first and re-welding then, the accuracy of the welding position is guaranteed. After assembly, finishing and surface treatment are further performed. An oxidizing film is formed on the surface of the guide plate through anodizing, so that the corrosion resistance and the hardness of the aluminum alloy are greatly improved. A finishing coat is also sprayed to the surface of the guide plate, so that the guide plate is more attractive, and the corrosion resistance of the guide plate is further improved. According to the guide plate manufactured by the manufacturing method provided by the invention, the self weight of the structure is greatly reduced while certain rigidity is guaranteed, and the integral cost is lowered.