The present disclosure relates to an automatic forming machine for plant growth supports, comprising a ring rolling system with a ring rolling unit, a mold system with a mold unit, and a welding system, which are all disposed on a machine frame, wherein the ring rolling unit can roll a metal wire and make the metal wire be formed into a ring with an opening in the mold unit; the mold system is for carrying the ring and making two free ends of the ring with an opening aligned or alternately overlap with each other; the welding system welds can weld the opening of the ring carried by the mold unit, causing the ring to become a closed ring. The present disclosure has a high automatic degree and can reduce the production time and labor cost.
