Abstract: Aiming at the defects of low photoelectric conversion efficiency, short life, low radiation intensity and poor uniformity in the xenon lamp solar simulator, a spherical array LED solar simulator was presented which was based on LED solar simulator optical system.The design methods of collimating optical system, uniform light system and spherical array LED light source system were studied.Firstly, the technology of coaxial transmission optical system was used to design the collimating optical system with double-separation structure.Followed on the basis of analyzing the performance and the composing form of the frequent optical system, the design process of integrator and field diaphragm was described.And then based on the design idea of spherical light source, the design of spherical LED array light source system was finished.Finally, the optical system was simulated and verified by Lighttools optical design software.The results showed that the irradiation non-uniformity is less than 3.86% with greater than 1100 W/m² irradiation intensity when the spherical array LED solar simulator was at a working distance of 100 mm and within the range of 100 mm× 100 mm.