Based on the actual application of air-dropped torpedo, the dispersion law of air-dropped torpedo and the active acoustic homing principle of torpedo are analyzed. The torpedo dropping error model, the submarine positioning error model, the hunting trajectory model and the homing detection model were established. The process of torpedo dropping and hunting was simulated by Monte Carlo method, and the effects of different torpedo dropping heights, velocities, mine dropping positions and submarine positioning errors on torpedo hunting probability were analyzed. The simulation results show that the analysis can provide a theoretical basis for operational decision-making.