Abstract: Carbon fiber is easily oxidized in a high-temperature oxygen-containing environment. The strong interfacial reactions with the matrix result in deterioration of their performance, which limits their use in carbon fiber-reinforced composites. In this paper, a C-Si₃N₄ protective coating which has high-temperature anti-oxidation performance was formed by constructing a polyacrylonitrile (PAN) layer and an organopolysilazane (OPSZ) layer on the surface of carbon fibers with curing at low-temperature and cracking at high-temperature. The results of scanning electron microscope and energy dispersive spectrometer show that the coating of PAN layer is helpful for Si element to adhere to the surface of carbon fiber. Increasing the concentration of the PAN solution from 1% to 3%, the relative content of the Si element increased from 2.81% to 8.26%. The tensile strength of PAN-OPSZ/carbon fiber prepared with PAN and OPSZ concentration of 3wt% was only 2.08% lower than that of uncoated carbon fiber, indicating that it did not cause obvious damage to the mechanical properties of carbon fiber. The oxidation resistance of the as-prepared PAN-OPSZ/carbon fibers was significantly improved, with a mass loss of less than 8wt% in an air atmosphere at 700℃, while the mass loss of uncoated carbon fibers was as high as 70wt%. The above results show that the PAN-OPSZ coating can effectively improve the high temperature oxidation resistance of carbon fibers, and has a very broad application prospect in the field of reinforced composites.