The invention discloses an antibacterial mildewproof polyurethane composite material containing natural plant and a preparing method thereof. The composite material comprises component A and component B with a ratio of component A and component B being 100:(20-50) by weight. The component A by weight comprises: 30-60 parts plant oil polyether polyols； 20-50 parts polyether polyols I； 5-20 parts polyether polyols II； 5-20 parts composite plant extract； 0-0.5 parts catalyst； 0.5-2 parts surfactant； 0-2 parts cross-linking agent； 1.5-3 parts foaming agents. The component B by weight comprising 20-50 parts modified MDI. The composite material made according to the preparation method of the invention shows a good stability and the polyurethane products made according to the preparation method is degradable. The antibacterial mildewproof natural plant adopted by the composite material in the invention enables the composite material to prevent the bacteria breeding effectively and provides environmental protection.
