The invention provides an aluminum-based composite material vehicle brake disc preparation method, which comprises: 1) pretreatment of reinforcement particles; 2) composite fusion casting; and 3) machining and heat treatment. According to the present invention, the volume content of the ceramic reinforcement body in the aluminum-based composite material is high (20-45%), and the near-final moldingof the aluminum-based composite material vehicle brake disc can be achieved through the composite fusion casting method; the method has advantages of simple and efficient process, low preparation cost and mass production; the weight of the prepared aluminum-based composite material vehicle brake disc is reduced by 50-60% compared to the weight of the cast iron brake disc, the thermal conductivityof the prepared aluminum-based composite material vehicle brake disc is improved by more than 2 times, and the prepared aluminum-based composite material vehicle brake disc has good high-temperaturewear resistance; and the wear of the prepared aluminum-based composite material vehicle brake disc is only 0.33-0.36 mm after the vehicle provided with the prepared aluminum-based composite material vehicle brake disc drives 20000 km, such that the aluminum-based composite material vehicle brake disc is expected to replace the cast iron vehicle brake disc, and can provide assistance for the lightweight of the vehicle.