The present invention discloses a digital photolithography method for a fiber optic device (FOD) based on a DMD combination. In this method, reflected light modulated by two DMDs is simultaneously projected onto a same position on an optical fiber end surface through one reduction projection lens. The two DMDs form a primary and secondary digital mask for joint control of an exposure dose distribution formed when patterns are shrunk and projected onto the optical fiber end surface. After the optical fiber end surface coated with photoresist is subject to this dose of exposure, developing, fixing, and etching are conducted, to form a micro-optic device on the optical fiber end surface. In the present invention, distribution of the exposure dose jointly modulated by a digital mask combination formed by the primary and secondary DMD exceeds an order of modulation of an exposure dose by a single DMD.