Abstract: In order to compare and analyze the degradation effects of different supercritical fluids on carbon fiber/epoxy (CF/EP) composites, CF/EP composites were degraded by supercritical fluids in batch reactor firstly, the degradation capabilities of supercritical CO₂ and supercritical alcohols at different reaction temperatures for CF/EP composites were analyzed, and the select method of supercritical fluid for the degradation of CF/EP composites was proposed. Then, the mechanical properties and microstructures of carbon fibers recycled using supercritical n-butanol and supercritical n-propanol were analyzed by testing measures such as single filament tensile tests, SEM and atomic force microscope etc. The results show that the degradation capability of supercritical CO₂ for CF/EP composites is weaker, and the degradation capability has significant improvement when using n-propanol as the entrainer. Supercritical n-butanol has the strongest degradation capability for CF/EP composites, followed by supercritical n-propanol, and the degradation capability of supercritical methanol is the weakest. The smaller the dielectric constant of selected reaction medium is, the greater the dipole moment is, the closer the solubility parameters with the epoxy matrix is, the easier for the degradation of CF/EP composites under supercritical conditions. Carbon fibers with excellent performances could be obtained by degradation of CF/EP composites using supercritical fluids. Comparing with the original fibers, the retention rates for single filament tensile strength of supercritical n-butanol and supercritical n-propanol recycled carbon fibers are above 98%, and the Weibull modulus are close.