A colordifference detection of light guide in the automobile system is designed in this paper. This system consists of a computer, a highperformance CCD camera hardware platform and a LabVIEW software of national instruments platform.First, use the computer to control the CCD camera to acquire the image of the normal and defective light guide. Then segment these images based on a method of histogram threshold segmentation. At last, transform these images’ color model from RGB model to CIELAB model, then apply the color difference formula CIE L*a*b* and CIE2000 to calculate and contrast the colordifference values between the normal and the detective images.So then finish the detection of colordifference of light guide in the automobile.