This study proposes a requirement analysis and verification methodology considering the interacted relationship among technical requirements, functional properties and disciplinary performance via requirements fitness and satisfaction evaluation and optimization studies for the conceptual design of unmanned aerial vehicles (UAVs). During the requirement analysis phase, flight mission requirements are associated with alternative configurations, establishing a requirement fitness model to determine the optimal UAV configuration. Next, on the basis of the UAV configuration, functional properties are derived from its aerodynamic and weight evaluation using a multidisciplinary analysis approach. The technical requirements and functional properties are employed by the requirement confirmation and validation A weighted Euclidean distance is calculated between actual and ideal functional properties to quantify requirement satisfaction. A satisfaction threshold is then set to construct an iterative validation optimization model, forming a closed-loop for UAV conceptual design. Results show that this method can effectively generate UAV configuration with a fitness level of 0.938%, and it can achieve an overall requirement satisfaction level of 0.6716.