Abstract: In a complex supply chain system，because of confidential information between vendors，then there will be between suppliers incomplete information competition game.Based on the similarity between the first-price sealed auction and the suppliers’ bidding of the supply chain，this paper studies the suppliers’ competitive bidding by using the first-price sealed auction model.The suppliers’ bidding game model is established，and the optimal bidding strategies of the vendors are gained.It resolves quantificationally the problem of the bidding in the incomplete information，and provides reference for decision-making bid to the vendors.