The invention provides a folded thin film capacitor and a fabrication method thereof. The folded thin film capacitor comprises a metal thin, two metal spraying layers (4a and 4b), two electrode terminals and a shell, wherein the two electrode terminals are respectively connected with the two metal spraying layers (4a and 4b), the folded thin film capacitor is characterized in that the metal film comprises a first metal evaporation film (2a), a second metal evaporation film (2b) and an electrical insulation polymer basic layer (1), the electrical insulation polymer basic layer (1) is sandwiched between the two metal evaporation films (2a and 2b), the metal film is repeatedly folded to form a cuboid block in a longitudinal direction, folded angles of the first metal evaporation film (2a) and the second metal evaporation film (2b) are superposed to respectively form a first side surface and a second side surface of the block, and the two metal spraying layers (4a and 4b) are respectively arranged on the first side surface and the second side surface. By the folded thin film capacitor and the fabrication method thereof, the problem that a metal spraying electrode at an end part of the thin film capacitor is seldom in contact with a metal film contact point is solved, heat generation of the end part of the capacitor is reduced, the internal inductance and the internal resistance of the capacitor are reduced, the lifetime of the capacitor is prolonged, and the folded thin film capacitor is particularly suitable for the field of large-current application.