The invention relates to a degradable polymer composite material. The composite material is prepared from the following raw materials in parts by weight: 10-30 parts of polystyrene, 30-50 parts of aliphatic polycarbonate, 15-30 parts of a propylene-propylene glycol copolymer and 15-30 parts of polyhydroxybutyrate-co-hydroxy hexanoate. Preparation of the degradable polymer composite material is achieved by a method of combining solution blending with melt blending; and the composite material fully plays a synergistic effect of various components, and has relatively high degradation capability and thermostability and relatively high mechanical property.