A compound modified plastic-wood composite material board is prepared by modified wood meal, plastic particles, styrene-acrylonitrile-maleic anhydride terpolymer, calcium stearate, terpene resin, modified chopped glass fiber, graphene, white oil and an anti-oxidant, has the characteristics of higher mechanization degree, less labor requirement, low manufacturing cost, environment friendliness, high modulus and rigidity, anti-creep, good waterproof and anti-corrosion performance, worm damage avoidance, season cracking prevention, excellent mechanical property, long service life and the like, and can be extensively applied to various fields of traffic, decoration, municipal gardens, packaging and the like.