Abstract: By designing the orthogonal test of electro-spark deposition under the line contact condition between cylindrical electrode and substrate, the influence of electrode diameter, electrode thickness and electrode rotation speed on the mass transfer efficiency, deposition efficiency and surface roughness of the coating is analyzed, and the parameters of the cylindrical electrode are optimized. The results show that under certain test conditions, a more uniform and dense coating can be obtained by using cylindrical electrode. With the increase of electrode diameter and electrode rotation speed, the number of gap discharges increases, sparks and splashes increase, and the surface roughness of the coating increase, the mass transfer efficiency and deposition efficiency decrease. As the electrode thickness increases, the number of short-circuit discharge increases, the number of no-loads decreases, and the mass transfer efficiency and deposition efficiency increase. The major and minor factors affecting the quality transfer efficiency and deposition efficiency of the coating are electrode diameter, electrode rotation speed, and electrode thickness respectively in descending order. The major and minor factors affecting the surface roughness of the coating are electrode thickness, electrode rotation speed, and electrode diameter respectively in descending order. Under the optimized cylindrical electrode parameters, the mass transfer efficiency is 82.48%, the deposition efficiency is 0.336 mg/s, and the surface roughness is 0.072 mm. There are no defects such as cracks and pores in the coating, and it has a good metallurgical bonding with the substrate.