The invention discloses a smooth mirror surface processing technology based on a composite screen printing plate. The smooth mirror surface processing technology comprises the steps of screen pulling, that is, the composite screen printing plate is manufactured from a screen plate, a silk screen and a hot melt adhesive film; pretreatment, that is, the composite screen printing plate is cleaned, and grease and impurities on the surface of the composite screen printing plate are removed; distribution and film attaching, that is, sensitive emulsion and a release attaching film are attached to the composite screen printing plate in sequence; plate burning, that is, a pattern is transferred to the composite screen printing plate from a film through ultraviolet irradiation; and developing, that is, non-cured sensitive emulsion on the composite screen printing plate is removed, and a finished product is obtained. By means of the smooth mirror surface processing technology based on the composite screen printing plate, the flatness of the printing surface of the composite screen printing plate is greatly improved, pulp can be effectively prevented from overflowing, the pulp is saved, lines can be printed thinner and straighter, and therefore a better printing silver line height-width ratio is obtained, the photoelectric conversion efficiency of products is improved, and the product competitiveness is improved.