Manufacturing method of aluminum alloy supporting rod for open wagon

The invention provides a manufacturing method of an aluminum alloy supporting rod for an open wagon. The manufacturing method comprises the following steps: casting an aluminum alloy round cast ingot; the aluminum alloy round cast ingot is bent after being subjected to first heat treatment; performing secondary heat treatment on the aluminum alloy round cast ingot; and groove milling treatment is conducted on the two ends of the aluminum alloy pipes and the two ends of the aluminum alloy round cast ingot, punching is conducted after the aluminum alloy pipes are assembled to the two ends of the aluminum alloy round cast ingot, and the aluminum alloy supporting rod is obtained. According to the manufacturing method of the aluminum alloy supporting rod, the strength of the aluminum alloy round cast ingot can be remarkably improved by sequentially conducting the first heat treatment, the bending and the second heat treatment on the aluminum alloy round cast ingot, the strength of the two ends of the aluminum allo