Unevenly distributed color image and image shadow of the pads on printed circuit board(PCB) are problems in an automatic visual inspection system.This makes it difficult for material classification and local threshold determination.In this paper,an illumination method with high uniformity by using four fluorescent lamps is proposed to eliminate the image shadow for the inspection of printed circuit board.The simulation and experimental results indicate that the method is appropriate in removing the image shadow of PCB image.Furthermore,this method can enhance the image contrast,so defects are also detectable.This method can be also applicable in other specular non-planar surface inspection systems.