▎ 摘　　要

NOVELTY - Composite preservative comprises alcohol amine compounds, benzoxazole/thiazole compounds and alkanolamide phosphates. USE - Composite preservative used for preparing hydraulic fluid (claimed). ADVANTAGE - The composite preservative has strong flame resistance, environmental friendliness, good metal anti-corrosion performance, and especially good aluminum anti-corrosion performance. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following: (1) a method for preparing composite preservative, which involves mixing alkanolamide phosphate, alcohol amine compound and oxazole/thiazole compound at 60-100degrees Celsius; and (2) a hydraulic fluid, which comprises composite preservatives and additives.