China set the goal of achieving carbon peak before 2030 and carbon neutrality before 2060 in 2019. However, as early as 2010, China had initiated pilot projects for low-carbon pilot policy for the first time. This pilot policy marked China's initial effort to tackle carbon emissions and is considered as the primary and immediate measure of carbon control before the establishment of carbon peaking and carbon neutrality goals. This study examined the carbon reduction effects of the provincial low-carbon pilot policy. The synthetic control method is employed to compare the actual carbon emissions of the pilot provinces with those of a composite control group. Given that Guangdong and Hubei are the provinces of implementing the low-carbon pilot policy and the carbon emissions trading scheme during a similar timeframe, it is necessary to assess the combined impact of these two policies. The research findings show that the low-carbon pilot policy has yielded positive results in terms of carbon reduction in the majority of pilot provinces. Yunnan, Liaoning, Hubei, and Guangdong have shown notable reductions in average annual carbon emissions, with percentages of 16.02%, 10.22%, 18.04%, and 9.29% respectively. In addition, Guangdong and Hubei, which have implemented both the low-carbon pilot policy and the carbon emissions trading scheme, have demonstrated more favorable outcomes in terms of carbon reduction, with more absolute emission reductions. These findings are helpful to derive insights regarding the effectiveness of policy implementation in achieving carbon reduction. The effect of the low-carbon pilot policy exhibits significant heterogeneity.Provinces implement both low-carbon pilot policy and CETS have better effects.Carbon reduction measures in five pilot provinces to overcome the uncertainty.