Unmanned aerial vehicle (UAV) swarm tactics have emerged in recent years as a new approach to both attack and defense, capable of altering the course of warfare. However, limited research exists on evaluating the operational effectiveness of anti-UAV swarm systems, and commonly used evaluation methods have significant limitations. To address this, a method is proposed for evaluating the combat effectiveness of anti-UAV swarm systems by combining fuzzy analytic hierarchy process (FAHP) and criteria importance through intercriteria correlation (CRITIC) methods to determine weightings, followed by the application of an improved TOPSIS method. First, an evaluation index system for the combat effectiveness of anti-UAV swarm systems is developed using the OODA loop (observe, orient, decide, act), a decision-making framework. Second, the FAHP-CRITIC method calculates the weightings of the evaluation indices. Third, the improved TOPSIS method is used to rank and optimize the effectiveness values of different schemes. Finally, the proposed evaluation method’s correctness and rationality are validated using control experimental data. A more scientific approach for evaluating the combat effectiveness of anti-UAV swarm systems is provided.