<p>Arc hybrid machining technology has demonstrated significant potential in the manufacturing of difficult-to-cut materials, owing to its high material removal rate, broad material adaptability, and low tool wear. The present study systematically reviews characterisation methods for the electrical, chemical, and thermal properties of electric arcs. It distinguishes the differences and connections between arc machining, electrical discharge machining, and electric pulse machining in terms of energy interaction mechanisms and process characteristics. Furthermore, it focuses on the principles and research progress of hybrid processes combining arc with vibration, laser, mechanical cutting, and electrochemical methods. A plethora of studies have demonstrated that the synergy of multiple energy fields has the capacity to enhance machining efficiency and surface quality with a high degree of effectiveness. In the future, it is anticipated that intelligent control, integrated additive-subtractive manufacturing, and digital twin technology will collectively drive the advancement of arc hybrid machining towards enhanced precision, efficiency, and intelligence.</p>