Abstract: The growth trend of carbon emissions in China as a whole is slowing down, but the effects of carbon emissions reduction among low-carbon pilots are quite different. Although the pilot cities all carry out low-carbon development related policy making, the mechanisms directly affects the effects of the policy implementation. Based on qualitative comparative analysis and field investigation, this paper analyzes the influence mechanisms of China's low-carbon pilots on carbon emissions reduction. It provides inspiration for China to move towards the goals of carbon peak and carbon neutral from a perspective of policy implementation. The results show that the financial support mechanism, power guarantee mechanism, monitoring and accounting mechanism and information disclosure mechanism are of great significance for carbon emissions reduction. The financial support mechanism and the monitoring and accounting mechanism are the necessary conditions for achieving the carbon emissions reduction target, while the power guarantee mechanism is the sufficient condition for achieving the target. The target responsibility system and talent guarantee mechanism have not effectively promoted carbon emissions reduction. In the absence of target responsibility system and talent guarantee mechanism, information disclosure mechanism can effectively promote low-carbon development through public participation. The policy implications are as follows: promote special funds and power guarantee mechanism for low-carbon development, improve the combination mechanism of the monitoring and accounting system and the target responsibility system, and refine the linkage mechanism between information disclosure and public participation.