C/C-ZrC-SiC composites have high specific strength, high specific modulus and good resistance to high-temperature ablation. At the same time, ZrC, SiC and carbon matrix materials have low neutron absorption cross-sections, which are candidate materials for future nuclear energy systems. In order to assess the application possibility of C/C-ZrC-SiC composites in the field of nuclear energy, C/C-ZrC-SiC composites was irradiated with ion beam of 2 MeV Si²⁺ at room temperature. Then the effect of Si²⁺ ion beam irradiation on the performance of C/C-ZrC-SiC composites was examined by means of grazing incidence X-ray diffraction, Raman spectroscopy, transmission electron microscopy, scanning electron microscopy and nanoindentation test, in terms of their crystallographic structure, lattice damage, microstructure, surface morphology and micromechanical properties etc. The results show that the irradiation of Si²⁺ion beam can induce stress within the SiC lattice, which then leads to an increase in the interplanar spacing of SiC, while the ZrC lattice does not expand; After irradiation, Raman peaks of SiC are broadened and shifted, correspondingly new peaks emerged in the Si-C region; The ion irradiation can induce carbon vacancies within ZrC, resulting in the formation of characteristic peaks; The surface morphology of ZrC, SiC and carbon fiber don't change significantly after irradiation, but the atomic ratio of carbon atom in ZrC and SiC increase by 13.03% and 23.21%, respectively; A large number of interstitial defect clusters appeared in ZrC, while SiC was partially amorphized, and a completely amorphized region appeared at the junction of ZrC and SiC grains; The I_D/I_G value and the interplanar spacing of graphite crystallites increase, and the layered structure of pyrolytic carbon is destroyed and gradually disordered; the nano-hardness and elastic modulus of ZrC, SiC and carbon fibers increase, with the best stability with the smallest degree of increase in nano-hardness and elastic modulus.