In this paper, a simulation study on the hit probability of an anti-torpedo torpedo(ATT) intercepting an incoming torpedo is con-ducted. A mathematical model of anti-torpedo torpedo interception trajectory is established. Through Monte Carlo simulation cal-culation, the influence of four errors on interception probability of anti-torpedo torpedo intercepting non-guided torpedo is quan-titatively analyzed. In addition, according to the principle of anti-torpedo torpedo interception fixed advance angle guided torpedo, by analyzing the movement trajectory of the incoming torpedo, ATT, and ship, the influence of the ship on the interception proba-bility under the three offset situations is simulated and calculated.