The influencing factors on electrostatic spraying under normal pressure and vacuum states were studied. Comparative experimental method was used in vacuum and normal pressure electrostatic environment to do spraying experiment according to the paint particle movement pattern. Result shows that in vacuum environment, the oil usage, the degree of finish and homogeneity, the speed of solidify are all better than that of in normal pressure. Finally, it is determined vacuum degree, electrostatic voltage, atomizing pressure, sector pressure and paint curing agent are some factors influencing painting quality.