Steel beam machining device

The invention provides a steel beam machining device. The steel beam machining device comprises a portal support and conveying rollers. The portal support is matched with the conveying rollers. The portal support is provided with a cross beam. A traction rod is arranged on the cross beam. A bottom groove of the traction rod is clamped and fixed to drawing rods of a welding trolley. Pulleys are arranged on the cross beam, and chains are assembled inside the pulleys. One end of each chain is fixedly connected with the corresponding drawing rod of the welding trolley. A welding gun is arranged on the welding trolley. According to the structure of the welding trolley, fixed rods are arranged between two supporting plates, fixed clamping plates are arranged at the two ends of the supporting plates, each drawing rod is fixed to two corresponding fixed clamping plates; the ends of each fixed rod and each drawing rod are both provided with threads and provided with bolts, the two sides of the bottom of each supportin