TiC/AlMgSc aluminum matrix composites were fabricated by selective laser melting. The phase composition, microstructure, recrystallization distribution and mechanical properties of aluminum matrix composites were systematically analyzed by X-ray diffraction, scanning electron microscope and universal testing tensile machine. The increase of dislocation density and TiC strength relative to alloy strength was calculated theoretically. The results show that the dislocation density of TiC/AlMgSc composites increases by 105% to 0.72×1014 m-2 with the addition of TiC reinforced particles, the proportion of <1 μm grains and sub-grain boundaries increased significantly, and the degree of recrystallization decreases. The tensile strength, yield strength and elongation reached 611 MPa, 589 MPa and 11.0%.Compared with AlMgSc alloy, the yield strength increased by 70 MPa and the elongation decreased by 1.1%.