[Objective] The temporal and spatial evolution patterns of regional agricultural carbon budgets and carbon emission fairness were investigated, in order to provide scientific references for formulating differentiated emission reduction and carbon sequestration strategies. [Methods] Based on the agricultural statistical data of Shaanxi Province from 2000 to 2020, this study estimated the carbon budget of cultivated land in the province for 21 consecutive years using the carbon emission coefficient method. A carbon emission fairness evaluation model was constructed to analyze the carbon-emission fairness of cultivated land in Shaanxi Province from two aspects: ecological carrying capacity and economic efficiency coefficient. [Results] ① The total carbon emission of cultivated land in Shaanxi Province increased first and then decreased during 2000—2020, and the carbon emission intensity increased by 48.15%, with chemical fertilizers as the main source of carbon emissions. ② The total carbon absorption continued to rise, with an average annual growth rate of carbon absorption intensity of 13.67%, in which vegetables having the highest contribution to carbon absorption. ③ Both carbon emissions and carbon absorption showed a high distribution pattern in Central Shaanxi Province and a low one in Northern and Southern Shaanxi, with the ecological carrying capacity of cultivated land carbon emissions being Southern Shaanxi > Central Shaanxi > Northern Shaanxi and the agricultural economic efficiency being Southern Shaanxi > Northern Shaanxi > Central Shaanxi. The results of carbon emission fairness cluster analysis showed that Southern Shaanxi and Xi’an shared the pressure of carbon emission reduction of cultivated land for other regions of Shaanxi Province to a certain extent, while Tongchuan City, Baoji City, Yulin City, and Weinan City regions increased the pressure of carbon emission reduction of cultivated land. [Conclusion] The dynamics and fairness of cultivated land carbon budget in Shaanxi Province vary greatly among different regions; thus, differentiated emission reduction strategies should be developed and improved according to different regional conditions.