The invention provides an optical glass with rather low transition temperature, high transmittance, chemical stability and good devitrification resistance, wherein the refractive index is 1.60-1.65 and the Abbe number is 62-66. The optical glass comprises, by weight percentage, 30-50% of P2O5, 35-50% of BaO, 2-6% of B2O3, 0-5% of La2O3, 0-5% of Gd2O3, 0.1-5% of Al2O3, 0.1-5% of Li2O, 2-10% of MgO, and 2-10% of CaO. According to the present invention, P2O5 is applied as the network generation body of glass so as to give high transmittance to the glass; a large amount of BaO is a key component for improving the transmittance of glass while improving the refractive index and weather durability of glass, and also the advantages of low transition temperature, good chemical stability and good devitrification resistance are provided.