For positioning and tracking submarine effectively, optimizing deployment of passive directional sonobuoy has been researched in anti-submarine tactics. Based on passive directional positioning principle, the positioning precision under different buoy array was firstly simulated and analyzed, getting deployment principles of tracking submarine. And then filtering model of tracking submarine was simply summarized, optimal deploying process of passive directional sonobuoy in the underwater target tracking was proposed. Finally, the existing method of buoy’s tracking submarine was improved. The simulation results show that improved buoy deployment method can meet demand of continuous and effective tracking of submarine.