Abstract:The establishment of ecological protection compensation mechanism is a critical content and an important institutional guarantee for the construction of ecological civilization. Carbon peak and carbon neutrality have been included in the overall layout of the construction of ecological civilization. The optimization of ecological protection mechanism based on carbon sink value plays a pivotal role in promoting the construction of ecological civilization in China, which is an important means of regulating the fairness of "carbon neutrality" process, and will also promote the transformation of ecological protection compensation policy to refinement. Based on the connotation, attribute and realization path of carbon sink value, this paper points out that the ecological protection mechanism based on carbon sink faces three challenges. First, the mechanism of carbon sink is complex, uncertain and unstable; second, the quantitative basis of carbon sink value is different; third, due to the influence of carbon price determination which is a fundamental and key element, the carbon sink value accounting is controversial and carbon sink monitoring technology is not well-developed. Therefore, the establishment of ecological protection compensation mechanisms based on carbon sinks should be carried out at different stages, and relevant basic theoretical research, management and technical support need to be deepened and improved.