<p>Cancer remains one of the most serious life-threatening diseases and a major threat to public health systems worldwide. Current diagnostic and therapeutic approaches face persistent hurdles, including toxicity resulting from the distribution of non-specific systemic anti-tumor agents, inadequate drug concentrations at tumor sites, and difficulties in achieving precise tumor localization alongside integrated diagnosis and therapy. Therefore, there is an urgent need for more efficient treatment strategies and accurate diagnostic methods with minimal side effects. Metal nanomaterials (particularly those based on gold, manganese, silver, copper, and palladium), when used individually or in combination, have emerged as promising agents in bioengineered cancer therapy. These metal nanomaterials have gained significant attention in the field of biological imaging, cancer cell targeting, photothermal therapy, photodynamic therapy, chemodynamic therapy and immunotherapy. Moreover, metal nanomaterials-mediated drug delivery systems can achieve the ability to specifically initiate and control drug release in tumor regions by responding to specific exogenous stimuli (including temperature, enzymes, light stimulation, magnetic fields, and ultrasound stimulation) or endogenous stimuli of the TME (such as pH value, redox environment, or interstitial pressure), which is expected to further improve the therapeutic effect. In this review, we focus on the application of metal nanomaterials in cancer diagnosis and treatment, and discuss the promising strategies for effective treatment, with the aim of providing new ideas for the application of metal nanomaterials in clinical tumor treatment.</p>