In this article, the advantages and disadvantages of different methods to obtain mid-far infrared lasers as well as the latest research results are first introduced. Second, a detailed introduction of the latest research results on the optical nonlinear frequency conversion technologies in Harbin Institute of Technology is illustrated, including the acousto-optic modulated Ho∶YAG Q-switched lasers with different pulse repetition rates. Third, the Ho∶YAG lasers with different pulse repetition rates and the latest research results in high-power mid-infrared and far-infrared lasers with ZGP, BGSe and CdSe crystals in the nearest three years are also introduced. Finally, with the development of the ultrashort pulsed 2 μm laser, high power ultrashort mid-far-infrared lasers is prospected to become a research hotspot in next few years.