The supply chain relationship can play a “synergistic effect” as well as an “encroachment effect”, which is a “double edged sword” that affects the cost management decision making. We use the Shanghai and Shenzhen A share manufacturing listed companies from 2009 to 2020 as a sample to explore the relationship between supply chain concentration and corporate cost stickiness. The empirical results found that under the tripartite relationship of supply chain concentration, manufacturers, suppliers, and customers are more of a “mutual aid” effect. Supply chain concentration can suppress cost stickiness through information mechanisms and governance mechanisms. Further research shows that when the external macroeconomic policy uncertainty is low and the regional development environment is poor, the supply chain concentration shows a stronger inhibitory effect on cost stickiness; In addition, the increase of enterprise financial flexibility is also beneficial to promote the inhibitory effect of supply chain concentration on cost stickiness; When the enterprise is a non state owned enterprise, the inhibition effect is more significant. The research conclusion of this paper affirms the positive role of supply chain concentration in reducing cost stickiness, and further discusses the internal and external conditions for supply chain concentration to play the role of “synergy”, which is helpful for enterprises to give full play to the positive impact of supply chain relationship.