Good operational support applicability is the key to ensure that unmanned underwater vehicle can successfully complete the designated tasks. The unmanned underwater vehicle has dual attributes of platform and ammunition equipment,and has the operational support characteristics of long-term storage,repeated use and maintainability. Depending on the full life cycle of unmanned underwater vehicle,and combined with its basic operational support workflow,this article puts forward completeness of operational support task based on task decomposition and standard support capabilities. The completeness is used as a comprehensive index for the operational support applicability,and analysis of examples are given combining the practical cases of equipment. This evaluation method has good practicality and maneuverability,and serves as a comprehensive and objective assessment of the process and key elements of operational equipment. The research results of this paper can provide a reference for the evaluation on operational support applicability of unmanned underwater vehicle and other similar unmanned platforms.