Abstract: In order to further explore the short electric arc machining (SEAM) process in air and reveal the crater formation and material removal mechanisms, air was used as the medium to explore the effects of air flow rates of 0 L/min and 20 L/min on the arc-molten pool and materials removal process, and a comparative experimental study was conducted. The results show that during the pulse duration, the arc goes through four stages: rapid expansion, deformation expansion, stability and extinction. In the arc expansion stage, the material is mainly removed by erosion particles. In the arc stabilization stage, the material is mainly removed by melt and erosion particles. In the subsequent extinguishing stage of discharge, the material is mainly removed by melt. In addition, the explosive force is easily generated in continuous pulse discharge, further increasing the amount of metal material removed. Increasing the air flow can increase the volume of particles removed and inhibit the occurrence of cracks.