The present invention relates to an aluminum matrix composite (AMC), and particularly to a method and apparatus for preparing an AMC with a high strength, a high toughness, and a high neutron absorption. The present invention combines a high-neutron-absorption and highly stable micro-B4C extrinsic reinforcement with an in-situ nano-reinforcement containing elements B, Cd, and Hf and having high neutron capture ability, achieves efficient absorption of neutrons by using the large cross-sectional area of the micro-reinforcement, achieves effective capture of rays penetrating gaps of the micro-reinforcement by means of the highly dispersed in-situ nano-reinforcement, and significantly improves the toughness of the composite material by means of the high-dispersion toughening effect of the nano-reinforcement, obtaining a particle-reinforced aluminum matrix composite (PAMC) having high toughness and high neutron absorption.