Developing novel antibacterial agents to combat bacterial infection has been an everlasting task for scientists, due to the drug resistance evolved by bacteria during antibiotic treatment. In this work, we used polydopamine (PDA) to modify MoS2 nanosheets (MoS2 NSs) and then grew silver nanoparticles (AgNPs) on their surface to form MoS2@PDA-Ag nanosheets (MPA NSs) as multimodal antibacterial nanoagents to treat Staphylococcus aureus (S. aureus) biofilms and S. aureus infected wounds. In vitro results show that treatment with MPA NSs under near-infrared (NIR) laser irradiation can efficiently eradicate the established S. aureus biofilms with 99.99% of the bacteria inside biofilms killed, which shows significantly enhanced therapeutic efficacy compared with the MPA only group or the NIR laser irradiation only group. Remarkably, MPA NSs were also successfully used to treat S. aureus infected wounds in mice under NIR laser irradiation. In vivo experiments demonstrate that about 99% of bacteria in wounds were killed and the healing of the infected wounds was promoted. Overall, this work demonstrates that MPA NSs with enhanced antibacterial activity are promising nanoagents to treat S. aureus biofilms and S. aureus infected wounds.