【原文】Disclosed a large-span bulk material conveying system, including a folding arm conveyor and a dike-striding elevation-type feeding conveying device. The folding arm conveyor is mainly composed of an undercarriage mounted on the ground of a stockyard, a tower body mounted on the undercarriage and provided with a gyration apparatus and a hopper, a balance arm provided with a balance trolley, a conveying arm provided with a portal frame I, a portal frame II and an unloading trolley, a tower top and other main components, wherein the balance arm, the conveying arm and the tower top are mounted on the tower body. The folding arm conveyor can rotate horizontally, and the conveying arm can be folded and retracted by controlling the wire rope by the windlass, so that the folding arm conveyor can be prevented from colliding with other devices or buildings during the rotation.