In order to improve the underwater defense ability of surface ship formation,building an underwater defense equipment system supplemented by unmanned surface vehicle is an important direction of future development. On the basis of summarizing the current situation and the development trend of unmanned surface vehicle at home and abroad,this paper analyzes the necessity of the development of unmanned surface vehicle. Combined with the task requirements of surface ship formation to defend against torpedo attack,the operational use method of unmanned surface vehicle is studied and its countermeasure effectiveness is simulated and evaluated. Relevant research results can provide guidance for the development and application of unmanned surface vehicle in the field of underwater information countermeasure.