In order to predict the fatigue life of aviation hydraulic pipelines reliably, on the basis of existing fatigue life prediction methods being insufficiency for hydraulic pipelines and in view of the stress characteristics of aircraft hydraulic pipelines, the types of loads acting on hydraulic pipelines are analyzed and their loads are decomposed, a fatigue life prediction method is proposed for the hydraulic pipeline under combined high and low cycle loading. Subsequently, a simulation analysis is performed on a specific type of aircraft hydraulic pipeline by using the Ansys Workbench to validate the effectiveness of the proposed method. Based on this analysis, fatigue life predictions are made in consideration of both high and low cycle loads, and under no consideration of the effects of high and low cycle loads. The results show that the effect of combined high and low cycle fatigue loads has a significant influence on the fatigue life of hydraulic pipeline. When the fatigue life of hydraulic pipelines is subjected to the prediction, it is necessary to consider the effects of both high cycle fatigue loads and low cycle fatigue loads simultaneously.