The mid-infrared laser at 2~5 μm is widely used in civil and military fields. It is one of the main ways to generate mid-infrared lasers by direct-pumping the laser gain medium. Because of the unique spectral properties, ZnS or ZnSe doped by the divalent transition metal ions of Cr2+ or Fe2+ (TM2+∶Ⅱ-Ⅵ) is one of the most promising mid-infrared laser gain materials. In this paper, the preparation of TM2+∶Ⅱ-Ⅵ materials are firstly summarized, and then the research progress on TM2+∶Ⅱ-Ⅵ laser ceramics is emphatically introduced. At last, the further research in raw materials and sintering is discussed. This paper could promote the development of TM2+∶Ⅱ-Ⅵ laser ceramics as well as the high performance mid-infrared lasers.