The invention relates to the field of plastic runways, in particular to a mixed plastic runway and a construction method thereof. According to the main points of the technical scheme, the mixed plastic runway comprises a pre-pavement layer, a base layer, a reinforcing layer and a surface layer in sequence; the pre-pavement layer is prepared from the following components in parts by weight: 25 to 30 parts of coal gangue, 15 to 20 parts of quartz sand, 3 to 5 parts of coal ash, 3 to 5 parts of talcum powder and 3 to 5 parts of bentonite; the above components are paved on a ground surface to formthe pre-pavement layer after being sintered and crushed; the base layer is prepared from the following raw materials: a mixed polyurethane adhesive, a catalyst, sodium carbonate and rubber particles;holes are preserved in the base layer; the holes are filled with the sodium carbonate; the reinforcing layer is prepared from the following raw materials: the rubber particles, an environment-friendly single-component water-cured plastic runway material and the sodium carbonate; the surface layer is prepared from the following raw materials: EPDM particles, self-setting varnished finish, the quartz sand and the sodium carbonate. The sodium carbonate is dissolved in water easily; water seepage holes are formed in the plastic runway after the sodium carbonate is dissolved, so that a water seepage function of the runway is enhanced.