Short electrical arc machining (SEAM) is a novel electro-machining technology, and it is suitable for machining all kinds of conductive materials with high machining efficiency. To improve the processing efficiency, a hybrid power system comprised of SEAM power source and a pulsed & direct current power source was implemented in SEAM. The influences of the combined pulse voltage produced by the hybrid power system on SEAM performance were studied, and Taguchi method was designed and carried out. The results indicated that material removal rate (MRR) increases and tool wear rate (TWR) decreases with the increase of combined pulse voltage, while the combined pulse voltage has a mild effect on surface roughness (Rz). Peak current is responsible for MRR in the machining process, while peak current and spindle speed are the dominant effect factors on TWR, and the effects of flushing pressure and peak current are responsible for Rz. Additionally, the higher the pulse voltage, the higher the MRR, the lower the TWR, and the relative electrode wear ratio (REWR). The MRR, TWR, REWR, and Rz decrease with the increase of flushing pressure.