Metal-organic frameworks (MOFs), a class of porous crystalline materials formed by the self-assembly of metal ions or clusters and organic ligands, have shown broad application potential in the biomedical field due to their high specific surface area, precisely tunable pore structure, designable framework composition, and good biocompatibility. This paper systematically reviews the synthesis and characterization of MOFs and their biomedical applications, with a focus on three key areas: cancer theranostics employing multimodal and combination strategies; drug carriers for the precise delivery and targeted release of biomacromolecules; platforms for in vitro diagnostic assays. Meanwhile, this paper analyzes the primary challenges that MOFs still face in clinical translation, such as scalable synthesis, long-term stability, and biological safety evaluation, and presents a perspective on future directions and application prospects.