Abstract: Different from other preparation processes, hot isostatic pressing (HIP) has the advantages of improving material density, inhibiting grain growth and avoiding grain orientation, and is often used to prepare polycrystalline 6HSiC materials. Silicon carbide has the characteristics of high melting point, high hardness, corrosion resistance, good thermal conductivity, and will not react with water to produce hydrogen, so it is one of the candidate materials for accidenttolerant fuel (ATF) cladding. In order to investigate the irradiation damage characteristics of polycrystalline 6HSiC prepared by HIP and evaluate the feasibility of silicon carbide material as ATF cladding under HIP process, the experiment took polycrystalline 6HSiC as the research object, and analyzed the properties and structure changes of samples before and after irradiation. In order to prevent the influence of other elements on the experiment, the irradiation ion was C4+, the irradiation dose was 1.8 dpa and 5 dpa, and a group of non-irradiated samples were set for comparison. The surface characteristics and properties of polycrystalline 6H-SiC before and after ion irradiation were analyzed by SEM, nano indentation, XRD and Raman spectroscopy. The results show that, with the increase of C4+ ion irradiation dose, the relative strength of the Raman curve of HIPSiC sample decreases gradually. Although C4+ irradiation damages the HIPSiC lattice structure to a certain extent, and the sample diffraction peak intensity decreases and shifts, the peak value changes slightly with the increase of the irradiation dose, indicating that the irradiation tends to saturate quickly. After C4+ ion irradiation, the sample material has defects and the nanohardness shows a decreasing trend, but the decreasing degree is not obvious. Therefore, the analysis of ion irradiation, the total number of polycrystalline 6HSiC antiirradiation capacity of the overall hip preparation, has the possibility of being the matrix of the fault in the future.