The wake-guide torpedoes are different from acoustic homing torpedoes in the aspects of guiding theory and trajectory control.In this paper,for providing the decision to submarine commander and promote the hit probability of torpedo,a model dissolving the launching parameter in the small shipboard angel situation is built;the influence of launching parameter to the torpedo trajectory is analyzed;and parameters in different situation are calculated.The results show:in different launching parameters,the seconded turning angel influences the torpedo trajectory most;and in the target moving factors,the shipboard angel is the biggest influencing factor;in the end the launching parameter in different situation is given and they can be helped when submarine attack in emergency and set the launching parameter manually.