Telescope with much larger primary can collect much more light and it is always pursued by the astronomers. Instead of using a monolithic primary, more and more large telescopes, which are now planed or in construction, invariably adopted segmented primary mirror. Therefore, how to sense and phase the primary mirror is the key technology. Unlike edge sensors, which need careful calibrations, dispersed Hartmann sensor (DHS) is non-contact method using broadband point light sources, and it can estimate piston by the two-direction spectrum formed by the transmissive grating’s dispersion and lenslet array. Thus it can realize the combination of co-focusing and co-phasing. In this paper, we introduce the design of our dispersed Hartmann sensor together with its principle. We also manufacture a DHS sensor and do real tests on our existing segmented mirror optics platform. Finally some conclusions are given based on the test results.