OBJECTIVE To prepare a new antibacterial agent triggered by near infrared light to combat bacterial infection and promote wound healing. METHODS The synthesis of antibacterial agengt was supported by the results from transmission electron microscopy, Ultraviolet-visible absorption spectroscopy and Fourier-transform infrared spectroscopy. The antibacterial agent was irradiated under near infrared(NIR) laser with different concentrations to study the photothermal properties. Release of ciprofloxacin from the antibacterial agent was determined under different conditions. Observed antibacterial activity of the agent by spread plate method and bacterial growth curve. The infected wound was made on the back skin of mice, and the mice were treated with different methods to observe the healing process of the wound and study its influence on the wound healing. RESULTS The synthesized antimicrobial agent could be heated repeatedly without attenuation under near-infrared light, and could still reach a high temperature of 45 ℃ at a low concentration of 125 µg·mL-1. At the same time, it could promote the release of loaded antibiotics, and the release rate reached 86%. Compared with 200 µg·mL-1 solution obtained by physical mixing of polydopamine and ciprofloxacin, the synthesized antimicrobial agent combined with near-infrared light showed more excellent antibacterial ability, and the bacteriostatic rate against Escherichia coli and Staphylococcus aureus was 99.9%. Antimicrobial agents with concentrations of only 0.312 5 µg·mL-1 and 1.25 µg·mL-1 combined with near infrared light significantly inhibited the growth of Escherichia coli and Staphylococcus aureus. Through the mouse skin defect model infected by Staphylococcus aureus, it was proved that the synthetic antibacterial agent still had excellent antibacterial effect in practical application, and could accelerate the healing of infected wound. CONCLUSION The synthesized antimicrobial agents have excellent antibacterial effect in vitro, and still have good antibacterial effect and promote wound healing under the conservative power irradiation without causing skin damage in vivo.