Two kinds of basic concentrators CPC and OMFC were introduced in principle respectively. According to simulation, the light paths in interior of concentrators were visual, so principles were validated and some generalizations were concluded. A new compounding-two-stage concentrator was researched based on above analysis, which was combined by OMFC as the first stage and CPC as second. In addition, an inverse paraboloid called deflector was developed depending on the attribution of mirror focus of OMFC. The performance of combined concentrator with deflector had been improved greatly comparing with without deflector, both in theoretical and simulative analysis. In this way, a high efficient two-stage concentrator has been developed which would be applied to solar green illumination system.