In order to maximize the available maneuvering overload when the missile enters the terminal phase, for a certain type of helicopter-borne missile, this paper builts a model to optimize the ignition time of its sustainer, considering the stability of the missile and the constraints of flight time. The results show that Hooke-Jeeves and ASA have reached a similar conclusion: the ignition time of sustainer is optimized to 30.1 s, ensuring the stability of the missile and the constraints of flight time, which increases the speed by 4.3% when the missile enters the terminal phase, thereby increasing the maneuvering overload in the terminal phase.