H-shaped steel column welding, overturning and lifting device and flange bottom plate welding method

According to the H-shaped steel column welding, overturning and lifting device and the flange bottom plate welding method, the overturning problem in the current H-shaped steel column welding process can be solved, the welding quality can be improved through the device, the welding speed can be greatly increased, the labor intensity of workers is effectively reduced, and the production efficiency is improved. The lifting device comprises a lifting support, an undercarriage and a lifting device, the undercarriage is arranged on the top face of the lifting support, and the tail end of the undercarriage is rotationally connected with the tail end of the lifting support; an overturning assembly which is used for fixing the H-shaped steel column and can drive the H-shaped steel column to rotate is arranged on the undercarriage; a lifting hook of the lifting device can be connected with the head end of the undercarriage and lift the head end of the undercarriage to turn upwards around the tail end of the undercarri