The structure and characteristics of asymmetrical compound parabolic concentrators with plane absorber (PACPC) is researched. The surface structure model of compound parabolic concentrators (CPC) with plane absorber is established, and the structural equation of PACPC is further established on the basis of CPC, and the analytic solution is obtained. The optics characteristic of the established PACPC surface structure model is simulated by the optical design software TracePro, and the optical characteristics are investigated. It is found that, with the change of incident angle of light, the radiant energy at the absorber surface is distributed unevenly. According to the solar direct and dispersion radiation theory, the acquisition of direct and scattered radiation in the course of the year is calculated by numerical calculation. The results show that the average annual lighting quantity obtained by the system of PACPC is obviously more than that of the plane absorber system with same area, and the increment is 15.28%.