The work examines the process of second harmonic generation in nanoparticles made from materials with a high refractive index . Second harmonic is a phenomenon in which photons of a primary frequency are converted into photons of a secondary frequency of twice the frequency, which is important for various applications in optics and photonics. We examine in detail the physical processes underlying second harmonic generation in nanoparticles, including nonlinear optical effects associated with the high refractive index of materials. For this purpose, the method of multipole decomposition of scattered radiation is used. The authors also discuss possible applications of second harmonic generation in nanoparticles, such as the creation of compact and efficient light sources in optical devices. The work presents important research results in the field of second harmonic generation by nanoparticles made of a material with a high refractive index. The research results can be useful for the development of new optical devices with improved performance and efficiency characteristics