The resorcinol–formaldehyde (RF) aerogels composited polyacrylonitrile (PAN) pre-oxidized fibers were prepared by a sol-gel method combined with the CO₂ supercritical drying technique using resorcinol (C₆H₄(OH)₂) and formaldehyde (HCHO) as the precursors andSsodium carbonate as catalyzer respectively, enhanced frame support by PAN pre-oxidized fibers in the solvent. The sample composition is characterized by using Fourier transform infrared spectrometer. Field emission scanning electron microscopy (FESEM), surface area and pore size analyzer were used to investigate the microtopography and the microstructure of the RF aerogels composited PAN pre-oxidized fibers with the nanoporous structure. Compared with the pure RF aerogel, the excellent thermal conductivity of the RF aerogels composited PAN pre-oxidized fibers is 0.032W/mK at 25°C and Young"s modulus of 1.499MPa has increased 0.6 time.