Airline maintainable parts of whole aircraft are one of the important products in forward maintenance design of civil aircraft. The traditional determination method is based on the composition of existing aircraft finished parts, strongly relying on the technical resources and support provided by suppliers. It cannot consider the needs of maintenance design at the beginning of product design, carry out independent forward maintenance design, and establish an economic comprehensive indicator system for monitoring and feedback. It cannot apply and practice direct maintenance cost analysis and control for civil aircraft throughout the entire life cycle, resulting in the final determined airline maintainable parts not meeting the needs of customers for replacement and maintenance and reducing maintenance costs. Based on the above shortcomings, this paper proposes a method for identifying and classifying airline maintainable parts of whole aircraft based on forward maintenance design, establishes the process of forward maintenance design of this method,analyzes the qualitative discrimination logic of this method,and determines the quantitative tradeoff index DMC of this method and establishes the engineering model for calculating the index.Finally,the method can be applied to the classification and tradeoff of airline maintainable parts through a numerical example.The results show that this research method establishes the maintenance forward design process for maintainable parts of the whole aircraft, can weigh and decide airline maintainable parts and classification of the whole aircraft, and can carry out maintenance activity design and economic index monitoring based on the maintainable parts of the whole aircraft. At the same time,it can iteratively update the redesign of airline maintainable parts and provide references for the redesign of airline maintainable parts.