Aiming at the disadvantages of low precision and slow speed of the traditional a lignment device,a flexible printed circuit (FPC) intelligent alignment device is designed and developed based on machine vision in this paper.Device uses high resolution industrial CCD camera to capture images,and helping wi th the mechanical and electrical parts,it can control the motion control card to complete FPC intelligent grabbing,acquisition ,processing and positioning.In the key location algorithm,the threshold segmentation of FPC image is mainly ac hieved using the improved OTSU algorithm,the average fitting of three ellipses is used to obt ain the coordinates of center of location circle,and the rotation angle is measu red using cumulative probability hough transform.The calculated offset relative to the standard posi tion is transmitted to the motion control card,and the closed-loop feedback control system is used for co rrecting the deviation. Finally,a large number of online experiments were carried out on the prototype. The experimental results show that the device has strong stability and high alignment accuracy,t he alignment error is not more than 0.06mm,and the angle error is not more than 0.0016rad.