Abstract: In this paper, a gap and flush measurement method based on line structured light is established by designing a visual inspection platform for washing machine surface quality. A gap measurement algorithm is designed. After threshold segmentation and gap positioning, on ROI image is obtained, and the least square method is used to fit the gap edge. The gap width is calculated according to the calibration results of line structured light sensor. A washing machine flush measurement algorithm is then designed. The light strip ROI image is obtained through the gap position. After threshold segmentation and centerline extraction, the feature points on both sides of the gap are found. The two-dimensional coordinates are transformed into threedimensional coordinates through the calibration results, then the flush depth is calculated. The experiment results show that the absolute error of gap width measurement is 0. 124 mm and the absolute error of flush size measurement is 0. 170 mm, which meets the requirements of automatic measurement for washing machines.