An improved 22dimensional Hough transform method to extract the laser spot parameters is proposed. Based on the gradient direction information of the selected first edge pixel in the image, the two others points are selected,and the three points are used as a group to compute the circle equation.It uses a 22dimensional accumulator array for circle center and a normalized 12dimensional radius histogram for circle radius respectively, and validates their existence by radius histogram. The proposed method is app lied into the processing of real laser spotimage, it has acquired good result in calculation time and detection accuracy.