The invention discloses a mica capacitor manufacturing method, which comprises the steps of: manufacturing a shell body, which is made of a high-strength insulating plastic material, specifically is of a rectangular parallelepiped structure penetrating left and right and has a cavity penetrating left and right inside the shell body; cutting mica paper into slices to obtain mica paper slices, wherein the size of each mica paper slice is equal to that of the cavity inside the shell body; cutting metal foil into slices, so that the width of the metal foil equals the width of the cavity inside theshell body, the length of the metal foil is twice over the length of the cavity, and the sliced metal foil is divided into two groups, namely the first metal foil and the second metal foil; and assembling the above materials. According to the mica capacitor manufacturing method, the metal foil is directly coated on the top part and the bottom part of the shell body in an epitaxial manner, thus the contact area of an electrode is increased, the use is facilitated, a copper core is omitted, the manufacturing cost is lower than that of an existing mica capacitor, the shell body adopts a reasonable formula and proportion, the components complement one another, and the shell body has the advantages of high strength, high insulation, flame retardance and ageing resistance.