Abstract: The active electronically scanned array (AESA) antenna is a critical component of an airborne fire-control radar, with its array face composed of numerous transmit/receive (T/R) modules. In current engineering practice, the reliability evaluation of AESA antennas is commonly conducted using a voting model based on the failure rate of individual T/R modules. However, this reliability evaluation method, which relies on a voting model, cannot directly account for the performance uncertainty and degradation processes of the AESA antenna array. To address these issues, this paper systematically applies Belief Reliability theory to construct a reliability evaluation framework for the airborne fire-control radar′s AESA antenna array. First, key performance parameters of the AESA antenna are identified to establish a performance margin equation. Second, the degradation process of the AESA antenna is analyzed, and simulation methods are used to calculate its performance while quantifying the associated uncertainties. Finally, a Belief Reliability evaluation model is established, and the Monte Carlo method is employed to calculate its reliability. By comparing with the traditional voting model-based method, the effectiveness and practicality of the proposed method are demonstrated.