Abstract: Background Quantitative evaluation of soil and water conservation carbon sink capacity in a region can provide theoretical and methodological support for improving the index system of soil and water conservation carbon sink monitoring and evaluation, promoting the development and trading of carbon sink of soil and water conservation, and achieving carbon peak and carbon neutrality goals. Guizhou Province is rich of vegetation and soil carbon storage, and has unique advantages of karst carbon sink. But there is currently a lack of provincial-level evaluation of soil and water conservation carbon sink capacity in Guizhou. Methods Selected Guizhou Province as the study area, based on the results of the first national water conservancy survey in Guizhou Province in 2011 and the completion of ecological construction tasks for soil and water conservation in Guizhou Province from 2012 to 2022, the terrestrial ecosystem carbon sink rate method, this study systematically calculated the carbon sink capacity of soil and water conservation measures in Guizhou over the years. Results 1) Carbon sink capacity of soil and water conservation measures in Guizhou Province is 6.37×107 t CO2 by 2022. 2) Among different indexes of carbon sink capacity of soil and water conservation, the carbon sink capacity of arbor forest land, enclosed arbor forest land, and benefit of soil and water conservation measures account for a relatively high proportion of carbon sink capacity, accounting for 42.73%, 26.33%, 22.64% of the total, reaching a total of 91.71%. 3) Annual increment in carbon sink capacity of soil and water conservation is generally showing a positive growth and upward trend.4) Ranking of soil and water conservation carbon sink capacity in various cities of Guizhou Province from highest to lowest is as follows: Bijie; Tongren; Qianxinan; Zunyi; Liupanshui; Qiannan; Anshun; Qiandongnan; Guiyang City. Conclusions Calculation indexes of soil and water conservation carbon sink capacity proposed in this study is capable of estimating the carbon sink benefits of regional soil and water conservation measures in Guizhou Province. The evaluation results can provide technical reference for further improving the carbon sink accounting system and for the next step of soil and water conservation carbon sink development and trading.