Aiming at the problem that part contour recognition in the recognition of thinwalled parts in industrial production lines is greatly affected by light, the color constancy technology is applied to the contour recognition of industrial production lines. Based on the basic principles of Retinex, HSI and edge detection algorithms, a contour feature recognition algorithm for thinwalled parts under complex lighting conditions is proposed for image restoration and contour recognition of thinwalled parts. First, the method uses HSI color space to extract the brightness of the image. Then the improved Retinex algorithm is used to perform adaptive image enhancement on the acquired part image and the light change information in the image is filtered out. Then the image is grayed out on this basis. Finally, the Canny algorithm is used to identify the edges of thinwalled parts, and the valid outline features of thinwalled parts are further extracted. Experimental results show that the algorithm can quickly and accurately identify the outline information of thinwalled parts under complex lighting conditions, and meet the needs of industrial assembly line inspection.