Abstract: The high content B₄C (B₄C≥30wt%) particle reinforced Al matrix (B₄C_P/Al) composites have excellent structural and functional properties, especially excellent neutron absorption performance, and are used as shielding materials in the field of nuclear protection. However, due to the addition of the high content B₄C particles, the deformation of the B₄C_P/Al composites is difficult. ABAQUS numerical simulation method was used to simulate the hot rolling process of B₄C_P/Al composites under different deformations. The B₄C_P/Al composites fabricated by hot pressing sintering were rolled at 480℃ and its microstructure and mechanical properties were analyzed. The numerical simulation results show that when the hot rolling deformation reaches more than 60%, the stress in the middle area of the B₄C_P/Al composite plate surface is small, while the stress in the side is large, and the residual stress is easily generated at the edge of the plate. The results show that B₄C particles in B₄C_P/Al composites distribute uniformly and the dislocation density increases with the increase of rolling deformation. When the rolling deformation reaches 70%, the yield strength of the B₄C_P/Al composite increases to 249.46 MPa and the ultimate tensile strength increases to 299.56 MPa. In the tensile process, the B₄C particles have the priority to fracture without the desorbed interface with the matrix. The B₄C particles bear the main stress, and the Al matrix has plastic flow, thus improving the strength of the B₄C_P/Al composites.