Pipeline welding device with positioning mechanism

The utility model relates to the technical field of line welding assistance, in particular to a pipeline welding device with a positioning mechanism, which comprises a welding device body, a sliding rack is fixedly connected to the lower surface of the welding device body, a supporting rod is arranged on the lower surface of the welding device body, and a sliding clamping groove is formed in the upper surface of the supporting rod. A supporting block is arranged on the supporting rod, a sliding rack is arranged on the supporting block, the sliding rack slides in a sliding clamping groove, a backup plate is arranged on the front side of the supporting rod, a rotating gear is fixedly connected to the surface of the front side of the backup plate, and a limiting clamping groove is formed in the surface of the front side of the backup plate. The rotating rod drives the supporting block to move rightwards, the supporting block drives the positioning block to move rightwards, the supporting block drives the rotatin