Abstract: The invention relates to the technical field of composites, in particular to a high-toughness and high-strength wood-plastic composite and a preparation method thereof. The wood-plastic composite is prepared from the following preparation raw materials in parts by mass: 30-50 parts of wood flour, 11-20 parts of high molecular weight polyethylene, 30-52 parts of polypropylene and 2-10 parts of an interface modifier. Polypropylene is used as a main component of a plastic matrix; high molecular weight polyethylene is used as a secondary component of the plastic matrix and has a toughening effect; wood flour is used as a filler to improve the strength of the wood-plastic composite; the interface modifier can improve the interface bonding between the wood flour and the plastic matrix, and all components have a synergistic effect, so that the obtained wood-plastic composite has high toughness and high strength.