This paper presents the design of a new Fresnel lens for GaInP/GaInAs/Ge multi-junction solar cells,with which uniformity irradiance distribution can be realized within the broadband solar spectrum from 300 nm to1800 nm.By actual tests,the quantum efficiency spectrum of GaInP/GaInAs/Ge multi-junction solar cells and refractive index dispersion curve of silicone,the body material of the lens are obtained.On this basis,the new Fresnel lens is optimized by combining the multi-wavelength and multi-focus method....