The invention discloses improved biological synthesis resin. The specific surface area and the surface situation of biomass are controlled, so that the percentage content of biomass in a biological synthesis resin product can be increased. The improved biological synthesis resin disclosed by the invention comprises the following components in percentage by mass: 30-60% a biomass micro powder composition, 10-50% of resin, 0.5-5% of a compatilizer, -.5-3% of a synthesis resin lubricating agent and 5-20% of an inorganic filling agent. By adopting a method disclosed by the invention, the specific surface area, surface group and surface computability of the biomass micro powder can be controlled, so that the percentage content of the biomass in biological resin and a composite material can be increased, the mechanical property and stability of the improved biological synthesis resin can be improved, and relatively good degradability, relatively low density and environment-friendly properties of a final product can be achieved.