In this investigation, graphene nanoplatelets reinforced pure titanium matrix (GNPs/TA1) composites were synthesized via short-term ball milling followed by spark plasma sintering. The mechanical properties and microstructure evolution of these composites were examined under both quasi-static and dynamic compression conditions. The results indicate that as the strain rate increases from 10−3 to 3000 s−1, the yield strength rises from 436.9 MPa to 1209.6 MPa, consistent with the positive strain rate effect. The superior yield strength of GNPs/TA1 composites arises from the dynamic Hall-Petch effect, dislocation strengthening and load transfer strengthening, with the contribution from load transfer strengthening being the most significant due to the reinforcement's (TiC-GNPs-TiC) facilitation of load transfer. As the strain rate increases, interfacial debonding gradually extends along the reinforcement and grain boundaries, but no macroscopic fracture occurred in this study. At a strain rate of 3000 s−1 during compression, {112‾2}, {101‾2}, and {11 2‾ 1} twins were generated. However, at a strain rate of 10 s−1, only {112‾2} and {101‾2} twins were produced, while {11 2‾ 1} twin was inhibited. Under high strain rate loading, the plastic flow behavior of GNPs/TA1 composites was predicted using the Johnson-Cook constitutive model, modified to account for adiabatic temperature rise, and the predictions showed good agreement with experimental results.