Post-treatment method for greatly improving performance of carbon nanotube film and application

The invention discloses a post-treatment method for greatly improving the performance of a carbon nanotube film and application. The post-treatment method comprises the following steps: infiltrating an original carbon nanotube film in chlorosulfonic acid for standing, then placing the original carbon nanotube film in air to enable chlorosulfonic acid molecules in the carbon nanotube film to react with water molecules in the air, then generating sulfuric acid molecules in the carbon nanotube film, and promoting the water molecules to enter the carbon nanotube film; then placing the carbon nanotube film in chlorosulfonic acid again, and enabling the carbon nanotube film to chemically react with water molecules to generate hydrogen chloride gas, so that the carbon nanotube film expands; drafting treatment is carried out, then soaking in the chlorosulfonic acid solution is carried out, and finally high-temperature vacuum annealing heat treatment is carried out. The tensile strength of the prepared carbon nanotube