Agricultural soils have significant carbon sequestration and reduction potentials to help mitigate climate change caused by human greenhouse gas emissions. To better understand the dynamics of soil organic carbon (SOC) storage and its driving factors in the North China Plain (NCP), this study combined meta-analysis, random forest machine learning, and satellite remote sensing data to study the spatio-temporal changes of cropland soil organic carbon storage and the contributions of its driving factors from 1981 to 2019. The results show that the cropland soil organic carbon storage of the top 0-20 cm in the NCP was (523.10±79.36) Tg C ((14.56±1.66) Mg C/hm²) from 1981 to 2019, with a growing rate of 5.94 Tg C/a (0.12 Mg C hm^-2 a^-1), which accounted for about 23.3% of the total annual increase of SOC in China's cropland. The total contribution of conventional cropland management options, including inorganic fertilizer use, organic fertilizer application and straw returning to SOC accumulation was 25.1%, 1.49 Tg C/a (0.03 Mg C hm^-2 a^-1). Compared with control experiments, inorganic fertilizer use (including nitrogen, phosphorus and potassium) increased the SOC sequestration rate by 22.7%-26.0%, organic fertilizer application increasing by 48.3%, and straw returning increasing by 23.4%. Meanwhile, the effects of such conventional management on SOC accumulation were modulated by soil physical and chemical properties. This phenomenon was more obvious under high temperature and precipitation conditions. It is worth noting that when the use of inorganic/organic fertilizer or straw returning exceeded the carbon and nutrient demands of crops and soil microbes, the SOC accumulation decreased significantly. Consequently, the SOC accumulation slowed down from 9.4 Tg C/a to 3.5 Tg C/a during the 2000s. In summary, the increase of cropland SOC in the NCP could be largely attributed to the improvement of cropland management in the past few decades, and the carbon sequestration potential in the NCP cropland is considerable. Nevertheless, it is essential to clarify the input amount of organic fertilizer, inorganic fertilizer, and straw for optimal carbon sequestration under varied climate and soil conditions, while ensuring crop yield.