An automatic non-standard steel welding production line comprises an automatic wing plate pushing system, wing plate conveying systems, an automatic web discharging and feeding system, an automatic T-steel welding system, an automatic T-steel turnover system, an automatic H-steel welding system and an automatic finished product conveying system. The wing plate conveying systems include an upper wing plate conveying system and a lower wing plate conveying system, and the wing plate conveying systems and the automatic web discharging and feeding system are arranged vertically. In the automatic non-standard steel welding production line, all the devices are simple in structure, easy to operate, stable in mutual connection, continuous automatic welding production of non-standard steel can be realized, weld seams on two sides of a plate are welded at the same time, and the automatic non-standard steel welding production line is small in distortion, less in capital investment, small in space occupation, suitable for non-standard steel manufactures with various scales, timesaving, laborsaving, manpower saving, high in working efficiency and good in product quality.