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.
