Combined cylinder body manufacturing method for aluminum-alloy liquefied petroleum gas cylinder

The invention discloses a combined cylinder body manufacturing method for an aluminum-alloy liquefied petroleum gas cylinder. The method comprises the steps of blank heating, cylinder body extruding and cylinder body welding. The method particularly comprises the steps that an aluminum-alloy round-rod ingot blank is cut into cylinder body blanks, and then the cylinder body blanks are put into a heating furnace for heating; and the heated cylinder body blanks are put into a mold cavity of an extruding machine to be extruded and formed into finished cylinder body products, and the finished cylinder body products subjected to extruding forming are spliced and welded into a whole, wherein the height of the mold cavity is h, and h is a positive number and larger than the height of a pressure head. According to the combined cylinder body manufacturing method for the aluminum-alloy liquefied petroleum gas cylinder, metal can flow uniformly in the extruding process; compared with parts manufactured through a traditio