There is an urgent demand in aerospace applications to develop titanium alloy materials with high specific strength, high-temperature resistance, and wear resistance. Hence, the TC4 titanium alloy composite material was developed through fabrication by laser cladding deposition (LCD) technology, and the effect of boron (B) content on its microstructure and mechanical properties was studied. The results show that the B element can significantly reduce the grain size of the TC4 titanium alloy as fabricated by LCD. The increment of B content exhibits grain size reduction from 1294 μm to 28.6 μm with 1% wt B content, which gradually weakens the columnar grain. The TiB acicular becomes precipitate at the β grain boundary as the B content increases. Consequently, the TC4 composite material"s hardness increases from 313.23 HV to 359.24 HV and tensile strength from 848 MPa to 1119.5 MPa. The research in this paper provides theoretical support for the application of additive manufacturing of high-performance platform-based alloy components with complex structures in the aerospace field.