The invention discloses a finished product packaging device for polyaluminum chloride production and a working method. The finished product packaging device comprises a first bottom plate and a secondbottom plate; a first clamping plate is fixedly installed at the position, close to the rear end, of the upper end of the first bottom plate, movable grooves are formed in the positions, close to thetwo sides, of the upper end of the first clamping plate, and movable blocks are inserted into the movable grooves; a second clamping plate is arranged at the upper ends of the movable blocks, a plurality of sets of grooves are formed in the upper end of the first clamping plate, and a plurality of sets of protruding blocks are arranged at the lower end of the second clamping plate; transverse plates are fixedly installed at the positions, close to the edges of the two sides, of the first bottom plate, long grooves are formed in the right ends of the transverse plates, and baffles are insertedinto the long grooves; and groove holes are formed in the positions, close to the two ends, of the left side face of each transverse plate in a penetrating mode, and screw rods are inserted into thegroove holes. According to the finished product packaging device, the position of a packaging bag filled with finished products can be limited, the packaging bag is prevented from moving in the sealing process, therefore the packaging bag is well sealed, and workers can conveniently convey the sealed finished products.