The invention discloses a barrel plating production line. The barrel plating production line comprises multiple barrel plating devices arranged in sequence; in the arrangement length direction of all the barrel plating devices, feed ports and discharge ports are respectively formed in the two end surfaces of all the barrel plating devices; conveying mechanisms are slidingly arranged on the adjacent end surfaces of two adjacent barrel plating devices; one ends of the conveying mechanisms extend into the barrel plating devices by the discharge ports of the barrel plating devices on the front sides, and the other ends of the conveying mechanisms extend into the barrel plating devices by the feed ports of the barrel plating devices on the back sides; connecting positions for enabling two adjacent ends to be positioned in overlapped areas and separation positions for enabling two adjacent ends to be positioned in staggered areas are vertically arranged at any one adjacent ends or two adjacent ends in at least one set of two adjacent conveying mechanisms; and any one adjacent ends or two adjacent ends in two adjacent conveying mechanisms move between the connecting positions and the separation positions to form the overlapped or staggered areas, so that plated workpieces are selectively input in the barrel plating devices for treatment by needed procedures according to the demands.