The evaluation of large aircraft suppliers' importance is crucial for supplier management and project stability. A method combining grey clustering and complex network theory is proposed for evaluating the importance of aircraft suppliers. The collaborative development network for the aircraft is first constructed through the work breakdown structure. Four centrality indicators of supplier network nodes are then employed, and a grey clustering model based on center-point mixed possibility function is applied to classify the suppliers. Taking the C919 aircraft as a case study, 43 suppliers are categorized into three levels. The roles and

relationships of suppliers at each level within the collaborative development network are analyzed. The effectiveness of the evaluation model is verified, providing management insights and strategic recommendations for optimizing supplier management for the aircraft manufacturer