In-situ TiC-TiB₂/Al-12Si composites were fabricated by ultrasonic assisted laser deposition using Ti、B₄C and Al-12Si powders as precursor materials at different proportions. The phase constitution, microstructure, frictional wear behavior of the composites were analyzed using X-ray diffraction (XRD), energy dispersive spectrum (EDS), optical microscope (OM), scanning electron microscope (SEM), friction and wear testing machine and 3D profile measurement. The results show that the α-Al phase is refined with the increasing of Ti+B₄C, rod-like TiB₂ synthesized in-situ can act as the heterogeneous nucleation core of α-Al phase. The TiC synthesized in-situ is a polygonal shape of 150nm. The wear resistance of in-situ TiC-TiB₂/Al-12Si composites is improved. The wear mechanism of Al-12Si alloy without Ti+B₄C addition is adhesive wear, and the wear mechanism of TiC-TiB₂/Al-12Si composites changes from adhesive wear to abrasive wear when the addition of Ti+B₄C is 8wt.%. When the addition of Ti+B₄C is 10wt.%, the wear mechanism of TiC-TiB₂/Al-12Si composites is adhesive wear.