Aquantitative evaluation program of health condition of aerospace propulsion system was presented to improve the operability of health condition evaluation of aerospace engines.There are several influential factors to the health of engines

such as: probability of fault

degree of fault and loss risk etc

all of which are random and fuzzy.With fuzzy evaluation theory

then grading of health condition of aerospace propulsion system was confirmed based on maximal membership rule and maximal fatalness rule.Fault simulation was conducted numerically for two sets of engines

showing that this method is applicable and reasonable.