EDM milling experiments on AISI 304 stainless steel (AISI 304 SS) using high-efficient hybrid machining with a high-speed air dielectric were conducted in this study. The novel and efficient hybrid machining is the arc machining and electrical discharge machining (EDM) working in parallel. AISI 304 SS can be quickly melted by significantly high machining energy and fast expelled by high-speed air flow and high-speed electrode rotation. The maximum material removal rate (MRR) of 5534 mm3/min was obtained, which was hundred times compared with that of conventional dry EDM. Comparative experiments on AISI 304 SS using high-efficient dry hybrid machining, dry arc machining, and dry EDM were conducted. The influences of air flow rate, peak current of arc machining, peak voltage of EDM, and electrode rotation speed on MRR, relative electrode wear rate and surface roughness were also studied. Moreover, the cross section and surface morphology were investigated. This study demonstrates that high-efficient dry hybrid machining is an efficient rough machining method in the processing fields that require removing vast materials.