Abstract: As extreme weather events occur more frequently, there is a global consensus to take strong action to combat climate change.Most of the Belt and Road countries are under great pressure to reduce CO₂ emissions due to the extensive economic development.Based on the panel data model, this paper analyzes the impact of Chinese investment on CO₂ emissions in the Belt and Road countries with different income levels.The results show that Chinese investment reduces CO₂ emissions in high-income countries, and has a weak impact on CO₂ emissions in upper-middle-income countries.However, Chinese investment significantly increases CO₂ emissions in lower-middle-income countries.Except for high-income countries that have achieved the carbon peak goal, there is no Kuznets curve in the Belt and Road countries.Economic growth and population lead to an increase in CO₂ emissions, while the improvement of energy efficiency contributes to carbon emission reduction.It is suggested to strengthen green and low-carbon investment in lower-middle-income countries that have not yet achieved the carbon peak goal.Establishing a multilateral cooperation mechanism is an effective approach.