The invention relates to a handrail welding worktable of a ventilation port cover for a spraying workshop. The handrail welding worktable comprises a transverse withdrawing frame and a longitudinal leg frame welded with each other; a chute is formed in the transverse withdrawing frame; two tabletops are slidingly mounted at the upper end of the chute; clamping blocks are mounted on the side surfaces, near the center of the transverse withdrawing frame, of the two tabletops in the front-back direction; semicircular clamping grooves are formed in all the clamping blocks; a long screw rod is mounted on the longitudinal leg frame through a bearing, and is formed by welding a left screw rod with a right screw rod with opposite spiral directions; the left screw rod and the right screw rod are both in threaded connection with the two tabletops in a one-to-one corresponding manner; and the left end of the long screw rod is welded with a handle. The handrail welding worktable is convenient for operation, only needs to manually rotate the long screw rod to oppositely slide the two tabletops to fixedly clamp all handrails, and is convenient for welding the handrails with outer frame edges of the ventilation port cover.