BaF2 crystal has been commonly used as UV-IR windows material due to its broad transmission spectrum 190-1200nm. It is characterized by high transmittance, slight hygroscopicity and little dependence of refractive index on the temperature. It is also a kind of sintillation material which has high energy resolution and time resolution, can simultaneously measure the energy spectrum and time spectrum, it shows excellent radiation hardness up to 106 rad or even more.