The use of natural proteins is a green and effective method for synthesizing silver nanoparticles (AgNPs). Aromatic amino acids of proteins play a reducing role in synthesis, and proteins are coated on the surface of AgNPs to play the role of stabilizers. In this study, we developed an efficient one-step method for synthesizing AgNPs using lysozyme (LYZ) under visible-light irradiation from a xenon lamp in situ. The light conditions and LYZ structure could substantially affect the synthesis. Antibacterial and scald-wound healing results showed that LYZ/AgNPs had broadspectrum and efficient antibacterial activity and promoted scaldwound healing. Therefore, the proposed synthesis method and LYZ/AgNPs have good practical application prospects.