The fixed solar concentrating system exhibits such advantages as wide heat-collecting temperature band, no tracking device, no mechanical movement, easy integration, and stable operation. Therefore, we study the critical component surface shape structure of the solar compound parabolic concentrators (CPC) with circular absorber. A theoretical model of surface shape structure of CPC with circular absorber is established and the analytic solution of the model is obtained. The optical characteristics of the theoretical model is validated by the optical design software TracePro. Meanwhile, a novel solar collector system with CPC is designed, and the calculation method for optical characteristics is established by the optical characteristics of surface shape of CPC with circular absorber. The numerical calculation is conducted by the optical characteristics of the designed system. The results show that the solar radiation collected by the solar collector with CPC is higher than that of the solar collector with evacuated tubes, and the average ratio is 34.57%.