Aircraft hydraulic energy system is the core power source to support the normal operation of key systems such as aircraft main flight control system, high lift system and landing gear. The system efficiency is an important design index of aircraft hydraulic energy system. In view of the lack of a perfect and effective method for the efficiency analysis of aircraft hydraulic energy system at present, an efficiency analysis method based on distributed simulation was designed. Combined with the working principle of the system, AMESim was used to establish the distributed simulation model of hydraulic energy system, and the relationship between the efficiency of hydraulic energy system and key indexes was studied under the condition of considering the loading work of hydraulic energy system in the whole flight process. A three-tier and two-level efficiency evaluation index system was established, and the efficiency of the index system was verified. The entropy weight method was used to analyze the relative weight of the efficiency index. The extended Bayesian fusion algorithm was used to study the component level efficiency and system comprehensive efficiency of the hydraulic energy system load in the loop during the whole flight of the aircraft. Finally, the real flight mission data of a aircraft were taken as example to verify the correctness of the efficiency analysis method.