The increasing diversity and escalating drug resistance of bacterial pathogens have significantly compromised the efficacy of conventional antimicrobial agents, creating formidable challenges in modern infection control. These developments underscore the critical need for innovative therapeutic strategies to address the persistent global health burden posed by microbial resistance. While metal-based compounds have been extensively studied for their anticancer properties in clinical applications, their potential in antimicrobial contexts remains relatively underexplored. This review systematically elaborates on the structure-activity relationship of metal complexes, with a focus on the unique characteristics of metal drugs that differ from organic small molecules. These drugs can overcome drug resistance through various mechanisms (such as generation of reactive oxygen species and penetration of biological membranes). Understanding these mechanisms provides a crucial basis for guiding ligand design and the development of delivery systems.