Conservation tillage is a crucial measure for enhancing the carbon sequestration and emission reduction capacity of farmland. Analyzing the spatio-temporal patterns and driving factors of its net carbon sink is of significant importance for achieving the national “dual carbon” goals. This study focuses on Shaanxi Province, utilizing data from 2000 to 2020, combined with the natural breakpoint method, standard deviation ellipse, and geographical detector on the ArcGIS 10.7 platform, to analyze the spatio-temporal distribution and driving factors of the net carbon sink from conservation tillage. The research results indicate the following: 1) The net carbon sink of conservation tillage in Shaanxi Province increased from 577.6 thousand tons in 2000 to 1 293.0 thousand tons in 2020, representing a growth of 123.86%. However, the growth rate varied across different stages, with soil carbon sequestration consistently being the major component. 2) The spatial distribution of the net carbon sink followed the pattern of “Guanzhong > Northern Shaanxi > Southern Shaanxi”, with the Guanzhong region consistently being the core area. The center of the net carbon sink exhibited a migration trend from “west-south-northeast”, with a particularly pronounced growth trend in Northern Shaanxi. 3) Factors such as the cropping index, agricultural mechanization level, and financial support for agriculture have a significant driving effect on the spatio-temporal evolution of the net carbon sink from conservation tillage in Shaanxi Province. Moreover, the driving force between different types of factors is stronger than that within the same type of factors. Based on these findings, it is recommended to strengthen policies related to subsidies for conservation tillage machinery and operations, implement targeted technical guidance, and encourage research institutions to develop adaptive agricultural machinery. These measures will further enhance the carbon sequestration and emission reduction benefits of conservation tillage, contributing more significantly to the agricultural sector’s role in achieving the national “dual carbon” goals.