In order to obtain the backscattering characteristics of triangular prism Au-Ge Janus nanoparticles (JNPs) in the solar spectrum, the discrete dipole approximation (DDA) method was used to simulate and calculate the backscattering efficiency of particle size, specific surface area, metal volume ratio and other factors. The results show that the position of the backscatter peak of triangular prism Au-Ge-JNPs is redshifted with the increase of triangular prism volume, and the peak intensity increases significantly. By adjusting the volume ratio of Au-Ge metal, it was found that when the ratio was 4:1, the backscattering efficiency peak reached the maximum. The relationship between the average backscattering efficiency and the equivalent radius of triangular prism Au-Ge-JNPs in the visible spectrum was analyzed, and the empirical formula was obtained, which provided a structural optimization design method for the regulation of the backscattering characteristics of Janus nanoparticles.