The invention discloses a micro-structural realization method on pyrolytic graphite substrate, belonging to a micro electromechanical technical field, the method adopts pyrolytic graphite as the substrate, and then performs the leveling, cleaning, insulating and re-cleaning of the substrate; the back of the pyrolytic graphite substrate is arranged with lithography alignment marks, multi-layer structure or high aspect ratio structure is formed by overlay; the front of the pyrolytic graphite substrate is sprayed with metallic film as seed layer, positive photoresist, lithography and develop are performed, and then electroplating mold is made so as to form an electroplating structural layer, after performing the positive photoresist, lithography and developing twice, positive photoresist is removed, ultrasonic cleaning is performed, and alumina is sprayed, and then the substrate is ground and is cleaned; the alumina is sprayed with the metallic film as the seed layer, and the seed layer is spread with SU8 negative photoresist, after performing the lithography, developing and electroplating, the SU8 negative photoresist is removed and the alumina is removed, so that the high aspect ratio structure is made on the pyrolytic graphite substrate. The invention has novel substrate materials and special processing performance.