As a laser gain media, rare-earth ion doped fluoride crystals have advantages of high transparency in a wide wavelength range, low phonon-energy, long fluorescence lifetimes and negative thermal dependence of refractive index, and can emit lasers from ultraviolet to mid-infrared. In this paper, the research progress of our group in the growth, optical and laser properties of rare-earth ion doped fluoride crystals (LiLuF4, LiYF4, BaY2F8, LaF3, PbF2, CeF3) are reviewed. The rare-earth ion co-doping effects of sensitization, deactivation, energy level coupling and emission spectra broadening are introduced, and the development trend of rare-earth ion doped fluoride laser crystal in the future is prospected.