In the present study, carbon nanotubes (CNTs)-silver nanoparticles (AgNPs)-co-doped polylactic acid (PLA) nanocomposites were prepared through two-solvent-assisted method. The morphology and structure of the prepared nanocomposites were characterized, and the thermal, mechanical and antibacterial properties of the nanocomposites were tested afterward. The results indicated that the CNTs and AgNPs were well dispersed within the PLA matrix, in which the CNTs and AgNPs attached with each other. The incorporation of these two reinforcement fillers significantly enhanced the thermal stability of the PLA. Due to strong intermolecular interactions, the CNTs and AgNPs improved the tensile strength of the PLA. Additionally, the prepared nanocomposites showed promising antibacterial effect on staphylococcus haemolyticus due to the existence of AgNPs. Having improved thermal and mechanical properties, as well as antibacterial capability, the prepared PLA nanocomposites have the application potential in packaging areas.