Abstract: Considering the variable flight profile of aircrafts and variable pressure variable displacement characteristics of intelligent pumps, a method for multiple model performance reliability analysis was developed. The transfer function models of two types operating modes were derived, the primary influencing factors were analyzed, and the phased mission reliability models were built based on the cumulative damage theory. A parameters optimization process was applied to the design of intelligent pumps, using the operating efficiency model as objective function and performance reliability index as constraint. The performance reliability of the individual operating phases was obtained for the optimized pumps, and its operating efficiency was compared with that of the constant pressure pumps, which are widely equipped in aircraft hydraulic systems. The results demonstrate that the method described tallies with the actual system operating conditions, and the high energy-saving performance of the intelligent pumps is considerable for its 15.8% more rising of average efficiency in contrast with the traditional constant pressure pumps.