A ray scanning device for a luggage conveying system. The device comprises a transmission apparatus, which transports an object under inspection to pass through a scanning region of the ray scanning device; and a plurality of scanning stages, which are respectively arranged on a plurality of scanning planes in the conveying direction of the object under inspection, wherein each scanning stage comprises a ray source module (10) and a detector group (30), which are arranged opposite one another, the ray source module (10) comprises a plurality of source points for emitting ray beams, and the ray source modules (10) of the plurality of scanning stages are respectively arranged on a lower portion, a left portion and a right portion of the scanning region.