Provided is an optical surface profilometer. The optical surface profilometer includes a Fabry-Perot resonator into which liquid crystals are inserted, a light source which supplies coherent light to the Fabry-Perot resonator, and a convex lens which is disposed in an interference pattern emitting plane of the Fabry-Perot resonator, wherein the coherent light supplied from the light source is incident to the Fabry-Perot resonator, wherein, when the light is incident, the Fabry-Perot resonator emits an interference pattern generated in a resonance mode, and wherein the interference pattern is configured so that a number of circular fringes having the same center are disposed non-linearly. As a voltage is applied to the liquid crystal layer of the Fabry-Perot resonator, an effective refractive index is changed, so that a resonance mode condition of the Fabry-Perot resonator is changed. As a result, a diameter of the interference pattern is also changed. A 3D surface profile of the object is measured by measuring and analyzing the change of the interference patterns.