The invention discloses a micro-arc oxidation solution for a titanium alloy strontium-containing biological coating. The micro-arc oxidation solution contains Sr(OH)2 with the concentration being 1-3 g/L or Sr(OH)2.8H2O with the concentration being 2-6 g/L, Na2SiO3 with the concentration being 4-8 g/L, NaH2PO4 with the concentration being 2-4 g/L, triethanolamine with the concentration being 2-4 g/L, Na2B4O7 with the concentration being 1-2 g/L and glycerol with the concentration being 5-10 ml/L, and a solvent is deionized water. The invention further provides application of the micro-arc oxidation solution. Titanium alloy is added into the micro-arc oxidation solution, a direct current pulse power source is adopted, voltage is controlled at 200-600 V, the current density is 0.1-0.4 A/dm<2>, the solution temperature is lower than 60 DEG C, time is 20-120 min, and the strontium-containing biological coating is formed on the surface of the titanium alloy. Compared with other medial titanium alloy surface treatment technology, the micro-arc oxidation solution has the beneficial effects of being high in treatment efficiency, firm in combination of a film layer and a base body and the like. Besides, because strontium, phosphorus and other active elements are added into the film layer, the biological activity is superior to that of an existing titanium alloy micro-arc oxidation treatment method.