In order to improve the logistics support capability of carrier-based aviation spare parts,the failure rate of carrier-based aviation equipment was studied based on similarity system theory and Bayesian theory taking a certain carrier-based logistics support demand as the object.The initial failure rate of aviation spare parts was determined on the basis of similarity system theory.With the application of Bayesian theory, the initial failure rate was amended based on the practically usage data of equipments.Finally,the theoretical application of it was presented with an example.