The present invention relates to a BWB wiring design system, and provides a BWB transmission wiring design system capable of guaranteeing the super high-speed operation of a system composed of a BWB and a plurality of printed circuit boards mounted on the BWB. The BWB transmission wiring design system consists mainly of a manager system that manages the wiring in the entire BWB system composed of the plurality of printed circuit boards, and a designer system that designs the wiring on each of the plurality of printed circuit boards while communicating with the manager system. The manager system presents the designer system predetermined design target values relevant to the entire BWB system. Moreover, the manager system presents the designer system the result of judgment made from design information, which is sequentially distributed from the designer system, on whether the design target values can be attained. The designer system finishes a wiring design while referencing the presented design target values and the presented result of judgment.