Abstract: In recent years, with the development of the economy, consumers have higher and higher requirements for corporate environmental protection, and more and more companies have begun to pursue green, low-carbon, and sustainable development. For example, the three-way catalytic converter technology in the automobile industry can effectively improve the utilization rate of gasoline and reduce exhaust gas emissions such as carbon monoxide; Heat pump technology and frequency conversion technology in the air conditioning industry can reduce energy consumption. However, in a competitive market environment, companies also need to consider the impact of competitors’ market pricing and environmental investment strategies when determining their own environmental technology investment decisions. This not only complicates the enterprise environmental technology investment decision-making process and the competition and cooperation game relationship, but also may lead to the imbalance of corporate decision-making incentives and the loss of corporate performance. As a result, by constructing three-stage game model between one supplier and two competing manufacturers, it is aimed to study how should manufacturers determine their environmental investment strategies and price strategies in a competitive market environment? How can manufacturers adjust pricing and environmental investment decisions to maintain their competitive advantage and maximize profits? And what impact will environmental technology investment have on supplier pricing, profits, as well as consumer purchasing behavior and consumer welfare?

Key words: environmental protection technology; market competition; quality differentiation; consumer welfare