Laser directed energy deposition technology was used to prepare 1 vol. % B4C/Ti6Al4V composites with varying process parameters in order to investigate the effects of process parameters (laser power and scanning speed) on the microstructure and mechanical properties of laser melting deposited B4C/Ti6Al4V composites and to uncover the relationship between the microstructure and mechanical properties of the composites under different process parameters. Based on the experimental results, the reinforcement of the composites consists of undissolved B4C, TiB, and TiC since the additional B4C particles are partially dissolved during the laser directed energy deposition process. As the laser power rises or the scanning speed drops, the quantity of undissolved B4C diminishes. Simultaneously, the quantities of in situ formed TiB and TiC increase, and the grain size of β Ti gradually grows. As laser power increases, the composites' hardness rises from 382.6 HV0.5 to 406.5 HV0.5. As scanning speed decreases, the hardness of composites likewise rises. The wear rate achieves a minimum of 8.517×10-4 mm3·N-1·m-1 when the laser power is 1200 W and the scanning speed is 500 mm/min. The tensile strength rises to 1180.4±6.2 MPa as the laser power drops or the scanning speed rises. The effect of grain refining is responsible for the increase in tensile strength.