Electro-deposited diamond wire saw, which is easy to manufacture with high bonding strength between deposited layer and substrate, has broad prospect in the application of slicing superhard crystals. Based on the principle of electro-depositing, the process of electrode depositing material onto, and thus metallurgically bonding with, substrate surface is analyzed. New equipment is designed with rotating electrodes and gas medium through analyzing the influence of depositing method and media on deposited layer. The electrodes is set at spark discharging state through adjusting their distance to the substrate. The distance is determined according to the average voltage between electrodes and substrate, which is used to detect discharging. It is found that the equipment works reliable and that it could deposit diamond grits onto φ0.4 mm stainless wire.