Garnet-based phosphor materials have some advantages of multi-site of doping icons, a wide option of doping ions, and a high efficiency of energy transfer, thus becoming a research hotspot for inorganic luminous materials. Compared with rare-earth ions, transition metal ions have superior features of spectral regulation and low cost. However, its luminous efficiency, valence, and luminous mechanism in complex lattice structures are still unclear. This review summarized the spectral characteristics and luminescent behavior of transition metal ions, especially Cr3+, Mn2+/4+. In addition, the application of transition metal ions in the fields of solid-state lighting, displays, biomedical imaging, and plant lighting was also represented.