The invention relates to a high-heat-resistance and high-fluidity polyamide composite material and a preparation method thereof. The high-heat-resistance and high-fluidity polyamide composite material is prepared from the following raw materials: polyamide 10T/11 resin, aliphatic polyamide resin, toluene diisocynate, 2,2'-(1,3-phenylene)-bisoxazoline, a coupling agent, alkali-free glass fiber, N,N'-ethylene diste, N,N'-bi(2,2,6,6-tetramethyl-4-piperidyl)-1,3-phthalic diamide, bi(2,6-ditert-butyl-4-methylphenyl)pentaerythritol octahydrogen tetraphosphate, an anti-dripping agent and dimethyl silicone oil. The high-heat-resistance and high-fluidity polyamide composite material has the characteristics of high heat resistance, high fluidity, high tensile strength and low water absorption, and can be applied to the fields of electronic electric appliances, LEDs (Light Emitting Diodes), automobiles, aerospace and military projects.