［Purpose/significance］ In order to improve the efficiency of knowledge management of complex product enterprises and provide help for the innovation of complex product enterprises in China,a knowledge management model under complex product situation is constructed based on modularization theory.［Method/process］ This paper reviews the literature on modularization and knowledge management,analyzes the process of modularization knowledge management,and constructs a complex product knowledge management model based on modularization theory.At the same time,the model is matched with the development process of domestic large aircraft to verify the effectiveness of the model.［Result/conclusion］ Modular knowledge management process consists of four stages:knowledge decomposition,knowledge matching,knowledge collaboration and knowledge integration.The model is helpful for complex product enterprises to define the knowledge management process,establish and improve the modular production system,and carry out efficient knowledge management activities,and provide reference for complex product research and development.