With characteristics of good underwater concealment and long passive detection distance of submarine-borne sonar，normally submarines can detect and attack target before surface ships. In order to effectively confront submarines，most surface ships use ship-borne helicopters to carry out anti-submarine search and attack. Aiming at the emergency that surface ships are threatened by underwater targets，the calculation method for torpedo release points of hovering aerial torpedoes attacking underwater targets in emergency state is analyzed and studied. The research results can provide reliable decision-making theoretical basis for army’s operational use of aerial torpedo.