Semi-automatic precise cutting and prefabricating device for pipeline elbows

The semi-automatic precise cutting and prefabricating device comprises a support, a fixing cylinder, a fixing frame and a magnetic cutting trolley, the fixing cylinder is fixed to the top of the support, a positioning hole is formed in the fixing cylinder, a to-be-cut elbow is arranged between the positioning hole and the top of the fixing frame, and a first fastening assembly is arranged on the circumferential side wall of the positioning hole; a second fastening assembly is arranged at the top of the fixing frame, the magnetic cutting trolley is arranged on the outer side of the fixing cylinder and provided with a magnetic roller magnetically attracted to the fixing cylinder, and a cutting torch is arranged on the side, facing the elbow to be cut, of the magnetic cutting trolley. One end of an elbow can be fixed through the fixing cylinder, the elbow can be conveniently cut by the magnetic cutting trolley, and the magnetic cutting trolley can do circular motion around the fixing pipe, so that the elbow is a