The invention discloses a manufacturing process of a subminiature-structure capacitor, and relates to a subminiature foil-type series-connection-structure thin-film capacitor and a manufacturing process of the subminiature foil-type series-connection-structure thin-film capacitor. The manufacturing process comprises the following steps of coiling, hot pressing, metal spraying, welding and packing, existing 3-mm-thick aluminum foils for 7.5 pitches are adopted as electrodes, three layers of electrodes are adopted, a layer of media is arranged under each electrode, the uppermost layer of electrode and the middle layer of electrode extend out of the edges of the media respectively, a metal spraying layer is arranged on the end surface of each electrode to be connected with the aluminum foil, a lead is welded to the metal spraying layers at the end surfaces and led out, the media and the electrodes are coiled and packaged with powder epoxy, and the capacitor is manufactured. The manufacturing process of the subminiature-structure capacitor is mainly used for overcoming the defects. The structure of the electrodes is changed, one layer of media is additionally arranged under each electrode, the wide aluminum foils serve as the electrodes, the distance between every two aluminum foils is reduced, the effective area is increased, utilization rate is improved, and the specific volume is increased.