PBO filament is an aromatic heterocyclic fiber composed of rigid functional units and has extremely high orientation along the fiber axis. This structure gives it ultra-high modulus, ultra-high strength, excellent temperature resistance, flame retardancy, With application properties such as chemical stability, impact resistance, wave permeability, and insulation, it is a new generation of super fiber used in aerospace, national defense, rail transportation, electronic communications and other fields after aramid fiber.