The invention including phosphate optical glass with refractivity ranging from 1.93 to 1.95 and the Abbe number ranging from 16 to 19, with a low liquidus temperature. The phosphate optical glass, including: 5 to 25 wt % of NaPO3, 1 to 20 wt % of KPO3, 2 to 15 wt % of P2O5, 0 to 5 wt % of BaO, 0 to 10 wt % of Ba(PO3)2, more than 0 but less than 2 wt % of B2O3, 5 to 25 wt % of TiO2, 35 to 55 wt % of Nb2O5, and 0 to 5 wt % of SiO2. Refractivity of phosphate optical glass can reach 1.93 to 1.95, the Abbe number can reach 16 to 19, the liquidus temperature is below 1,120° C., the processing property during melting is good, the glass surface is unlikely to be devitrified during the processing of the glass, and can be formed easily.