Titanium/magnesium alloy bimetal composites show promising prospects for lightweight applications. The Ti/Mg bimetal composite was fabricated in Ti-6Al-4V pyramidal lattice structure via AZ91D melt infiltration. Comparative analysis of the tensile and compressive properties was conducted between the composite and its constituent materials (Ti-6Al-4V lattice structure and AZ91D matrix). The tensile strength of the composite (95.9 MPa) was comparable to that of the Ti-6Al-4V lattice structure (94.4 MPa) but lower than that of the AZ91D alloy (120.8 MPa) due to gaps at the bimetal interfaces hindering load transfer during tension. The composite exhibited greater elongation (1.7%) compared to AZ91D (1.4%) alloy but less than the Ti-6Al-4V lattice structure (2.6%). The compressive performance of the composite outperformed that of the Ti-6Al-4V lattice structure, underscoring the significance of the AZ91D alloy in compressive deformation. Fracture analysis indicated that the predominant failure reasons in both the composite and lattice structures were attributed to the breakage of lattice struts at nodes caused by the stress concentration.