Abstract: An optical wavefront analyzer based on the phase-shearing interferometry technique for measuring a wavefront of a light beam is disclosed. The analyzer includes a single phase shifter, a driving device, a pattern receiving device, and a phase reconstructing device. A method of measuring a wavefront of a light beam is also provided for solving the problems of two-axial focusing and phase inconsistency encountered the prior art by employing phase-shearing and phase-shifting techniques to improve the method of optical wavefront mesurement. A non-iterative, path-independent unwrapping methodology is used to deal with a complicated wavefront.