A method of preparing a C/C-SiC composite part, including: preparing, using a solvent evaporation process, carbon fiber composite powders coated with a phenol resin; according to a three-dimensional model of a to-be-prepared part, forming a green part corresponding to the to-be-prepared part using the carbon fiber composite powders and a 3D printing technology; densifying the green part to yield a C/C porous body having a density of 0.7 to 1.1 g/cm3 and an open porosity of 30 to 50%; and siliconizing the C/C porous body under vacuum, removing excess silicon to yield a primary carbon fiber reinforced carbon-silicon carbide (C/C-SiC) body, densifying the primary C/C-SiC body, to obtain a final C/C-SiC composite part.