Considering the less information of early research-manufactory of the equipment, mismatching between determination methods of spare requirement and integrity index of combat, and greater uncertainty of spares relationship among the equipment readiness rate, the aircraft availability, the average downtime and the fill rate of spare parts are analyzed, thus determining the guarantee probability of equipment spare parts. Then, the Delphi method is used to distribute the spares fill rate of analysis system of equipment and LRU. Furthermore, the corresponding spare parts inventory limitation standard is obtained according to the interval requirement of the given aircraft readiness rate. Finally, the feasibility and rationality of analysis method are verified through the instance.