The invention discloses a balance beam intelligent welding method based on a robot welding production line. An MES issues a production line production scheduling instruction; a balance beam is manually hung and conveyed to a feeding and blanking station; manual code scanning confirmation is performed; an RGV automatically conveys the balance beam to an MES specified welding station; a welding robot performs welding seam welding in the balance beam according to offline program; after the welding is completed, the balance beam is conveyed to the feeding and blanking station by the RGV; the balance beam is manually hung and conveyed to a repair welding station for repair welding; a support pipe and an upper wing plate are installed; the balance beam is manually hung and conveyed to the feeding and blanking station again; the manual code scanning confirmation is performed again; the RGV automatically conveys the balance beam to the MES specified welding station; the robot performs weldingseam welding outside the balance beam according to the offline program; after the welding is completed, the RGV conveys the balance beam to the feeding and blanking station; the balance beam is manually hung and conveyed to the repair welding station; sealing plates at two sides of the box body, an electric pipe and an anti-shearing block are installed; the balance beam is conveyed off the line; and the manual inspection is completed. The method has the advantages that the work intensity of workers is reduced; the welding quality of the balance beam and the management level in the production process are improved; and the construction environment is improved.