The invention, which belongs to the new energy storage element field, discloses a packaging method for a lithium ion capacitor. The method comprises: a metallic housing, a cover plate, an aluminum leading-out terminal, and a matched sealing element are designed; and a tab with an electric core prepared is welded with the aluminum leading-out terminal, the electric core is assembled into the metallic housing after insulating and welding processing and an upper cover plate and the sealing element are installed, and drying processing and liquid injection are carried out and then preparation of a single lithium ion capacitor is completed. On the basis of the improved packaging material and structure, a novel high-airtightness and high-reliability lithium ion capacitor with simple series and parallel connection is obtained, so that the strength and vibration-resistant performance of the single capacitor and the assembled system can be improved, a heating problem of the working process can be solved, and the product reliability and the service life can be enhanced. Therefore, installation, structural strength, and application process current-carrying problems can be solved.