Plasmonic nanomaterials have attracted significant attention in recent years due to their exceptional near-field enhancement, photothermal, and photomechanical effects, resulting in remarkable progress in fields such as energy, catalysis, optics, and biomedicine. Particularly in biomedicine, their applications have played a crucial role in developing ultrasensitive biosensing strategies and effective therapeutic approaches. In this paper, we explore plasmonic nanomaterials from three key perspectives: near-field enhancement, photothermal effect, and photomechanical effect. We summarize the latest advancements in their applications in biomedical fields such as sensing, imaging, and therapy, and provide insights into future development directions in this field.