【Objective】 Carbon sequestration and emission reduction of farmland soil is an important area to realize the "dual carbon" strategy in agriculture. This study attempted to explore the impact of long-term crop cultivation on soil organic carbon (SOC) under different climatic conditions, soil properties, and agronomic measures, as well as to clarify the natural and artificial conditions conducive to SOC accumulation under long-term crop cultivation in China.【Method】 This study collected and sorted out 147 published literature on SOC changes in China during cultivation over 5 years from 1990 to 2022, and finally established 934 databases. Meta-analysis was used to quantitatively analyze the changes in SOC under long-term crop cultivation in China, and systematically analyze the influence degree of various factors.【Result】 Under the influence of climate, initial soil properties, and agronomic measures, the SOC content in the topsoil of long-term crop cultivation in China increased by 17.85% overall. However, the increase in organic carbon decreased with the deepening of the soil layer. The warm-temperate zone climate had the most obvious effect on SOC accumulation, reaching 33.62%. When at an altitude of 200～600 m, a temperature of 8～15 ℃, and precipitation of 600～1 000 mm, the accumulation of SOC was the highest, increasing by 28.90%, 35.11%, and 31.33%, respectively. In addition to pH and alkali-N, the increase in SOC under long-term crop cultivation continued to decrease with the increase of initial SOC, total nitrogen, and other available nutrients. When the initial nutrient content in the soil was at a low level (0～10 g·kg^-1 SOC, 0～0.9 g·kg^-1 TN, 0～10 mg·kg^-1 Olsen-P and 0～75 mg·kg^-1 Olsen-K), the increase in SOC was the highest, increasing by 35.65%, 44.72%, 24.98%, and 6.38%, respectively. In addition, all conventional agronomic measures currently have an increasing effect on SOC content. The total straw return had the largest increase in SOC, which was 33.62%. Long-term non-fertilization had no significant impact on SOC.【Conclusion】 The low altitude warm temperate zone in China was more conducive to the accumulation of SOC in farmland soil. As the soil layer deepens, the increase in SOC caused by long-term crop cultivation gradually decreases. In addition to alkali-N, soils with poorer initial nutrients (SOC, total nitrogen, Olsen-P and Olsen-K), are more conducive to the accumulation of SOC. Among various field management (straw returning, film covering, fertilization and tillage), total straw return is the most effective in promoting the accumulation of SOC. These research results are of great significance for achieving carbon neutrality and sustainable development in agriculture as soon as possible.