Abstract: There are two kinds of methods for reconstructing the original wavefront from its slopes, namely zonal method and model method. Different algorithms for the zonal method are investigated. The algorithm of obtaining generalized inverse of matrix by decomposition of singular value is considered superior to others in its faster calculation speed and good reconstruction accuracy.Once the wavefront is reconstructed,the terms of longitudinal and transverse focal shifts contained by a least - squares polynomial fitting , which are then corrected separately, so that thedynamic range for the phase correction is reduced. Examples of computer simulatedwavefront reconstruction and real -time wavefront reconstruction using wavefrontsensor are given. The method is especially suitable for arrayed large aperture adaptive optics systems , and for image procesing using shearing interferometry in optical measurements.