No arc plays the role of transition ignition and arc steering, and can be used as an auxiliary heat source. The non-arc anode is on the nozzle hole wall, and most of the heat of the arc is transferred to the nozzle and taken away by the cooling water, which is not conducive to the cooling of the nozzle and the stability of the surfacing process. Therefore, the current specification should not be too large, generally below 50A, even if it is retained during surfacing. According to the different specifications of surfacing workpiece, the arc-free current should be adjusted accordingly, and this data is not fixed.