The invention provides a super capacitor and a preparation method thereof. An electrode material for the super capacitor is a carbon nanoelectrode material; a current collector is carbon-coated porous metal; and the mass fraction of a carbon nano-material in the super capacitor is 20%-35%. The invention further discloses the preparation method. The preparation method comprises the following steps: dispersing the carbon nanoelectrode material into an electrolyte to form slurry; extruding the slurry into the porous current collector in a vacuum supply condition or a pressurized condition to form a composite structure of an electrode and the current collector; and finally welding the current collector and a metal tab, partitioning the composite structure of the electrode and the current collector by a diaphragm and carrying out packaging and molding. The super capacitor product obtained by the method has the advantages of being high in effective ingredient content, high in volume energy density and suitable for an aqueous electrolyte, an organic electrolyte and an ionic liquid electrolyte, and can be operated at 1-5V.