Low-density low-warpage automobile bottom protection plate material and preparation method thereof

The invention discloses a low-density low-warpage automobile bottom protection plate material which comprises the following components in parts by weight: 49-85 parts of polypropylene, 10-30 parts of glass fibers, 3-6 parts of a compatilizer, 0.5-5 parts of a foaming agent, 1-5 parts of a foaming aid, 0.2-1 part of a nucleating agent, 0.2-2 parts of an antioxidant and 0.2-2 parts of a lubricant, wherein the polypropylene is a compound of high-melt-strength polypropylene and high-fluidity polypropylene, and the glass fibers are flat short glass fibers. The low-density and low-warpage automobile bottom guard plate material obtained from the materials prepared from the components through a micro-foaming injection molding machine and a mold opening secondary injection molding foaming technology has the advantages that (1) the weight reduction effect of a bottom guard plate product is obvious, and the requirement for light weight of the automobile bottom guard plate is met; (2) the automobile bottom guard plate pr