Abstract: To meet the requirements for high accuracy and real time performance of high power laser driver beam automatic alignment, a fast and precise center location method for target of high power laser driver beam automatic alignment is proposed. The specific characteristics of the target edge are fully extracted by using multiple structuring elements-based generalized morphological edge detection, while the influences of the noises on images are diminished. Then, the edge is quickly located in sub-pixel precision by adopting the Lagrange polynomial interpolation method, at last the center position of the spot target in image is accurately acquired by using circle fitting method based on least square fitting method and geometric centroid. This algorithm is verified in the ShenguangⅡ upgrade device, the alignment time of eight prelight roads is less than 3 min, and the alignment time of the main light path is less than 7 min. The main output of the near-field beam collimation accuracy is better than 0.2%, and the far field accuracy is better than 0.2(RMS).