During the arrangement of lamps and lanterns in painting equipment, the DIALUX software is used to simulate the lighting layout in the painting workshop. The use of DIALUX software to simulate the lighting layout in the painting workshop are explained. According to the design scheme of the lamp arrangement to simulate the illuminance projected on the car body, so as to find a better arrangement of lamps, reduce the number of lamps, meet the requirements of illumination, and achieve the purpose of lean energy saving.