Abstract: 2D CF/SiC composites were prepared by liquid silicon infiltration. XRD analysis revealed that SiC only presents as β phase in composites. The mixed solution of K₃Fe(CN)₆ and KOH in the same mass ratio was used to corrosive the material. SEM images show that coarse and fine two morphological of the grains exist in 2D CF/SiC composites. It's conclude that distinguishing shapes of SiC are produced by two different growth theory: silicon atoms diffuse into carbon through the vacancy mechanism which leads to the appearance of amorphous SiC. As heat-retaining time increasing, amorphous SiC gradually transforms into the crystalline state. After the carbon atoms diffuse through the silicon carbide layer, carbon atoms dissolve in the liquid silicon and exist in the form of C—Si group. Under the influence of temperature gradient and concentration gradient, Si—C group move farther away from the C/SiC interface and begin to nucleate after reach saturation.Coarse silicon carbide crystals are formed by the dissolution-precipitation mechanism, which accompany the emergence of stacking fault.