The invention discloses a method for manufacturing a micro supercapacitor based on a graphene nanocrystalline carbon film electrode, which comprises the following steps of: 1, ultrasonically cleaninga Si substrate with SiO2 on its surface layer, and then sputtering and depositing an Au film, as a current collector of the micro supercapacitor, on the surface of the substrate by using a magnetron sputtering device; 2, placing the SiO2/Si substrate with the sputtered Au film on the substrate holder of an ECR plasma processing system, loading the SiO2/Si substrate into a vacuum chamber, and depositing a graphene nanocrystalline carbon film as the electrode material of the micro supercapacitor; and 3, dropping a prepared PVA/H3PO4 electrolyte onto the surfaces of the two prepared graphene nanocrystalline carbon films, then assembling the two graphene nanocrystalline carbon films face to face, placing the assembled graphene nanocrystalline carbon films at room temperature for 10 to 12 hours, and obtaining the graphene nanocrystalline carbon film-based micro supercapacitor after the electrolyte is dried to form a film. The method solves the poor compatibility between a traditional graphene-based micro supercapacitor electrode and the current collector.