The invention provides a halogen-free filling flame-retardant nylon 6 composite material and a preparation method thereof. The halogen-free filling flame-retardant nylon 6 composite material provided by the invention is characterized by being prepared from the following raw materials: 53-70 parts by weight of nylon 6 resin, 7-15 parts by weight of melamine cyanurate, 20-30 parts by weight of inorganic filling material, 0-5 parts by weight of synergistic flame retardant, and 1-5 parts by weight of processing agent. Compared with the prior art, the halogen-free filling flame-retardant nylon 6 composite material provided by the invention has the beneficial effects the halogen-free filling flame-retardant nylon 6 composite material is capable of passing the GWFI (Glow Wire Flammability Index) test at 960 DEG C, also has the characteristics of being low in cost, high in modulus and strength, excellent size stability, environment-friendly, flame-retardant and the like, and has good application prospect.