With the gradual maturity of unmanned underwater vehicle(UUV), the study of its application in modern underwater warfare is an important basis for improving the theory of future underwater warfare. This paper analyzes the operational requirements of UUV about covert pursuit,launching a surprise attack and confusing enemy and attack, and researches three operational modes of UUV: passive centralized type, semi-active distribution type and resident distribution type, from the perspective of improving underwater combat capabilities. In addition, in order to adapt to the future underwater high-intensity warfare, the key technologies such as deep-diving communication, autonomous control and underwater distribution and recovery of UUV are proposed to provide an important practical basis for the development of UUV combat theory.