The invention relates to a preparation method of a high-temperature structure-function combining B4C / Al 
neutron absorbing material. The preparation method comprises the concrete steps of (1) adopting a 
high energy ball milling method for ball-milling aluminum 
powder into flake aluminum 
powder; (2) placing the flake aluminum 
powder into an air furnace for pre-oxidizing, and forming a layer of nanometer aluminum 
oxide film on the surface of the aluminum powder; (3) uniformly mixing the pre-oxidized flake aluminum powder and micron-sized B4C particles; (4) pressing molding the uniformly mixed powder; (5) conducting 
pressureless sintering or hot pressed 
sintering on a pressing-molded pressing blank; and (6) 
forging, extruding or rolling a sintered billet so as to obtain the high-temperature structure-function combining B4C / Al 
neutron absorbing sectional material or 
sheet material. By adopting the method, a certain amount of nanometer aluminum 
oxide can be introduced into a pure aluminum matrix, and the micron-sized B4C particles are added, so that the aluminum-based 
neutron absorbing material with two-phase reinforcement of micron B4C and nano Al2O3 can be prepared, has both a neutron absorbing performance and an excellent high-temperature 
mechanical property, and can be applied in the fields of spent fuel 
dry storage, transportation and the like.