At present，there is a lack of comprehensive analysis and evaluation of commercial aircraft economic benefits for manufacturers at home and abroad. In this paper an index system for OEM is developed to evaluate commercial aircraft economic performance，which combined value analysis of technology economics and aircraft design engineering. Four layers index，including cost，product，business and market are established. Gray relational method is adopted to analyze a type of aircraft. Results show that this index system reflects the relation between commercial aircraft technology capability and market performance，which is in compliance with market regularity and will be useful in product planning，engineering evaluation，project demonstration and marketing strategy.