Abstract: A can body manufacturing system includes a can barrel forming apparatus, a printing apparatus, and a branch conveyor, wherein the can barrel forming apparatus is for forming can barrels, the printing apparatus is to perform printing on outer surfaces of the can barrels and includes a printing apparatus inlet conveyor, the branch conveyor is arranged in a post-process of the can barrel forming apparatus and includes a flow path switching unit, a first branch of the branch conveyor is connected to the printing apparatus inlet conveyor connected to the printing apparatus and is connected to a printed can manufacturing section, a second branch of the branch conveyor is connected to a bypass inlet conveyor not passing through the printing apparatus and is connected to a plain can manufacturing section, and printed cans and plain cans without being printed are producible by switching the flow path switching unit.