The invention relates to a high-heat-resistance high-flow nylon composite material and a preparation method thereof. The high-heat-resistance high-flow nylon composite material is prepared from nylon 6T/11 resin, aliphatic polyamide resin, toluene diisocyanate and 2,2'-(1,3-phenylene)-oxazoline, a coupling agent, alkali-free glass fiber, N,N'-ethylidene bis stearamide, N,N'-di(2,2,6,6-tetramethyl-4-piperidyl)-1,3-phthalic diamide, bi(2,6-ditert-butyl-4-methyl phenyl) pentaerythritol diphosphate, a dripping resistance agent and dimethyl silicone oil. The high-heat-resistance high-flow nylon composite material has the advantages of high heat resistance, high liquidity, high tensile strength and low water absorption and can be applied to the fields of electronic appliances, LEDs, automobiles, aerospace, military and the like.