A methodology for designing corneal topographier based on Hartmann-Shack sensor is described in this paper. Then,applying this method,an instrument is developed for measurement of corneal topography. In the system,the focus of an objective lens is precisely positioned on cornea′s curve center. Wavefront reflected from the surface of cornea can be measured by the H-S sensor which is conjugated to the cornea plane. Then,the surface data of cornea can be acquired by algorithms for reconstructing. The repeatability and precision of the instrument are also validated. And the difference between errors measured by the instrument and those measured by ZYGO interferometer is less than 0.0818λ (RMS). Data of human corneal topography was also measured.