Abstract: High voltage electrostatic spraying robot is widely used in automobile spraying industry,its core technical index is spraying coating efficiency. At present，due to the low conductivity of resin materials，irregular shape and other reasons，the spraying efficiency of bumper resin parts is low，resulting in the cost waste in spraying resin parts. This paper introduces the definition and measurement method of coating efficiency in electrostatic spraying of resin parts，studies the cutting-edge electrostatic spraying technology and key technical parameters used in the automotive industry，clarifies the key technologies and optimization methods to improve coating efficiency，and provides suggestions for building a resource saving and environmentally friendly society.

Key words: high voltage electrostatic spraying, spraying coating efficiency, bumper resin parts