A halogen-free flame-retardant long glass fiber reinforced high-temperature-resistant PA6T composite material is characterized by being prepared from the following components in parts by weight: 30-60 parts of nylon 6T, 20-40 parts of long glass fibers, 13-18 parts of DOPO, 0.5-1 part of an antioxidant, 5-10 parts of a compatibilizer, 3-5 parts of a triazine charring agent, 1-5 parts of a synergistic agent, 3-5 parts of polypropylene short fibers, 0.5-1 part of potassium carbonate whiskers, 2-4 parts of a talcum powder, 1-3 parts of silicon carbide, 0.5-1 part of a nucleating agent, 1-4 parts of a tackifier, 0.5-1 part of microcrystalline wax, and 1-3 parts of dioctyl phthalate. The composition is relatively simple, and the proportion is reasonable; by adding the nucleating agent and the tackifier, the polymer can be heterogeneously nucleated, high-temperature resistance, wear resistance and processing performance of the material are improved, and thus the intrinsic viscosity, the melting point and a molecular chain structure of polyester are changed, the PA6T melt quality is improved, and the overall strength of the PA6T material is enhanced.