The invention discloses a preparation method of phosphate antibacterial glass. The method comprises the following steps of (1) preparing the materials according to the following weight parts: 40 to 50parts of phosphorus pentoxide, 10 to 15 parts of silicon dioxide, 2 to 8 parts of aluminum oxide, 10 to 20 parts of sodium oxide, 2 to 5 parts of lithium oxide, 1 to 6 parts of magnesium oxide, 0.5 to 2 parts of manganese dioxide and 2 to 5 parts of antibacterial metal oxides; performing uniform mixing; performing flat milling for 1 to 2 hours; performing rotary milling for 30 to 50 minutes to obtain a mixed material; (2) melting the mixed material in step (1) under the condition of 1100 to 1200 DEG C; performing heat insulation for 0.5 to 1.5 hours at the same temperature to obtain glass molten solution; (3) pouring the glass molten solution into a preheated graphite mold to be shaped; performing quenching treatment on the obtained shaped glass to obtain the phosphate antibacterial glass. The phosphate antibacterial glass provided by the invention has good antibacterial performance, and has relatively good chemical stability.