In the context of global efforts to develop low-carbon economy and curb the growth of fossil energy, it is particularly important for supply chain enterprises to make scientific decisions on emission reduction and energy conservation. This paper investigates supply chain enterprises to make emission reduction decisions by considering cost-benefit of carbon emission reduction and internal and external factors changes. We analyze the dynamic game model of a three-level supply chain consisting of suppliers, manufacturers, and retailers in cooperative and non-cooperative states. The change of optimal emission reduction is calculated by differential game and dynamic analysis. The optimal profit is obtained from the corresponding optimal decision of enterprises, and the optimal proportion of manufacturers" share of emission reduction cost is studied. We adopt numerical simulation method to simulate decision-making evolution process of emission reduction. Finally, the impact of different influencing factors on product emission reductions, supply chain decisions and profits are shown. These findings can provide theoretical support and reference for multi-level supply chain decision-making.