Welding supporting frame for metal guardrail machining

The utility model discloses a welding supporting frame for metal guardrail machining, and relates to the technical field of metal guardrails. The device comprises a support frame, wherein the support frame comprises an I-shaped frame; support columns are vertically fixed at two ends of the I-shaped frame; a lifting rod is sleeved between the top end parts of the two supporting columns; extension rods are inserted into the two side surfaces of the lifting rod; overturning frames are rotationally connected between the two sides of the two supporting columns; the two ends of the overturning frame are connected with the extension rod in a sleeved mode. Supporting clamping bases are arranged between the upper surface of the extension rod and the two sides of the lifting rod in a linear array mode. The distance between the longitudinal rods is adjusted and placed through the supporting clamping bases arranged between the rectangular end sleeves located on the two sides of the extension rod and the two sides of the