Abstract: The total operational effectiveness of torpedo is an entire reflection of torpedo technologies and an important criterion for decision in process of torpedo development and operation. Based on the analysis of torpedo′s basic task and operational process, the performance evaluation is divided into six capabilities, including maneuver, detection, tracking,countercountermeasure, re-searching and lethality, and an evaluation indexes system of torpedo operational effectiveness is established. Making use of fuzzy theory, a comprehensive fuzzy evaluation method with step-by-step layers structure is presented to evaluate torpedo operational effectiveness. The feasibility and availability of the method is proved by several torpedo effectiveness evaluations. The application results show that the evaluation method is useful for the decisions on demonstration, development, operation，and improvement of torpedo.