System availability is an important index to measure the operational readiness of aircraft carrier arresting gear system, and an evaluation method for system availability of aircraft carrier arresting gear is proposed. By using the analytic hierarchy process, the reliability block diagram is constructed in the system dimension, and the Markov state transition process between repairable component availability and spare parts is constructed in the component dimension, and the equivalent sub-model is used to calculate the component availability, and the system availability evaluation method is established. The results show that the method is feasible and effective.