The invention relates to a magnetic rotating arc plasma generator, and belongs to the technical field of plasma generators. The magnetic rotating arc plasma generator comprises a cathode, a magnetic rotating arc anode, a rotational flow ring and an anode water channel, and is characterized in that the cathode and the magnetic rotating arc anode are arranged in a coaxial manner; the magnetic rotating arc anode comprises an arc starting anode, a transition anode and a main anode, the transition anode comprises a conducting section and an insulating section, and the main anode comprises an electromagnetic coil and a main anode body. The magnetic rotating arc anode is in the shape of a special-shaped circular tube on the whole, one end of the magnetic rotating arc anode is in the shape of a bell mouth, and the middle of the magnetic rotating arc anode is provided with a through hole. The air flow generates a rotational flow through the rotational flow ring, the electromagnetic coil generates an electromagnetic field, the rotational flow and the electromagnetic field compress the arc together and drive the arc to rotate, thereby enabling the root of the arc to rotate with a high speed on the main anode. The magnetic rotating arc plasma generator has the advantages of high arc voltage, low operating current, high electric-thermal conversion efficiency, small electrode ablation amount, small fluctuation range of arc voltage, wide power adjustment range, low operation cost, good disassembly and assembly characteristic, high practicability and the like.