The invention discloses a polypropylene (PP) composite material specially used for packaging bags, and a preparation method of the PP composite material. The PP composite material is prepared from the following raw materials in parts by weight: 30-40 parts of PP, 5-15 parts of polyethylene, 2-6 parts of polyformaldehyde, 3-8 parts of chitosan, 1-3 parts of silicon dioxide, 5-8 parts of sorbitol, 1-2 parts of titanium dioxide, 4-8 parts of sodium stearate, 1-4 parts of azodicarbonamide, 1-3 parts of pentaerythritol, 1-4 parts of an antioxidant, 2-5 parts of a stabilizing agent and 3-5 parts of a toughening agent. The PP composite material specially used for the packaging bags is wear-resistant, stable and waterproof, and is not easy to deform.