Two VUV-grade BaF2 windows with 05 mm-thick and 1 mm-thick respectively were selected to study the transmittance variety with the temperature. The results show that the cutoff wavelength of BaF2 crystals will shift towards the long wave with the increase in temperature. In a certain temperature range, BaF2 crystals can depress 130.4nm radiation well, and also has a high transmittance at 1356 nm. Compared with the reported method in which SrF2 crystals can be applied to suppress 1304 nm stray light by heating, BaF2 crystal can inhibit the 1304 nm emission line completely, and thus reduce the power consumption of the device at the same time. This indicates that BaF2 crystals can play an important role in the ionosphere optical remote sensing detection.