Abstract:The comprehensive performance of the aviation hydraulic oil was evaluated with the aviation hydraulic oil No.10 as an example.The effect of the three important indexes,the total acid,moisture and antioxidant content on the overall performance of aviation hydraulic oil was studied.By tracking detection and correlation analysis,the reason and trend of the indicators change of the aviation hydraulic oil was investigated,and the correlation between the three indicators was analyzed.The weight of each indicator was calculated and the membership functions were determined.An evaluation model was established by fuzzy reasoning method,and was used to evaluate the comprehensive performance of the aviation hydraulic oil.The feasibility of this evaluation model was validated by experimental data.The results show that the total acid value,moisture content and antioxidant content have a certain correlation.By detecting some indicators,the change of other indicators can be speculated indirectly.The evaluation result of this model is consistent with that of engineering practice,it provides the basis for the test analysis and replacement of hydraulic oil.