As the name suggests, carbon fiber not only has the inherent intrinsic properties of carbon materials, but also has the soft processability of textile fibers. It is a new generation of reinforcing fibers. Compared with traditional glass fiber (GF), Young's modulus is more than three times; compared with Kevlar fiber (KF-49), not only the Young's modulus is about 2 times, but also in organic solvents. Insoluble in acid and alkali, the corrosion resistance is outstanding. Some scholars immersed PAN-based CF in a strong alkaline NaOH solution in 1981. It has been more than 20 years since it has maintained its fiber shape.