Machine vision inspection is a popular detection method at present. Aiming at the problem of large number of assembly line production workpieces and low detection accuracy, a calibration method based on line structured light is adopted to realize batch detection of workpiece hole size and position information. The process includes a camera calibration method, the Hessian matrix line extracts the center line of the laser line, the laser plane fitting calibration, and the point cloud reconstruction of the passenger car pedal. Experiments show that the detection method of the camera system can measure the diameter of the hole in the range of 500mm, and the accuracy can reach 0.3 mm. It can meet the measurement requirements of the dimensional accuracy and position accuracy of the hole on the industrial site.