Soil organic carbon mineralization is the main way of carbon output, which directly affects soil nutrient cycling and atmospheric CO₂ concentration, and plays an important role in maintaining soil fertility and global carbon cycling. It is of great significance to explore the characteristics of soil organic carbon mineralization and influencing factors under different land use types, which is beneficial to understand the carbon cycling and ecological restoration in karst areas. Five land use types (corn field, grassland, Lonicera Japonica, planted forest and shrubland) were selected in Mashan County, Guangxi. The mineralization culture was carried out for 30 days, and the changes in soil and microbial properties were measured, which were used to analyze characteristics of soil organic carbon mineralization and its influencing factors under different land use types in karst areas. The results showed that: (1) Soil organic carbon mineralization significantly increased in the shrubland and planted forest compared with corn field, while there was no difference in grassland and Lonicera Japonica. However, the carbon mineralization potential of planted forest was larger and the carbon retention capacity was relatively weaker compared to other land use types, indicating that the high carbon loss potential in planted forest under human disturbance and global changes. High carbon sequestration capacity occurred in shrubland, grassland and Lonicera Japonica, indicating that the three land use types can retain more soil organic carbon. Thus, these can be used as the optimized model for Grain for Green in rocky desertification areas. (2) soil organic carbon mineralization in surface soil was higher than that in deep soil, but the higher carbon input, the lower soil organic carbon mineralization constant and the same carbon sequestration capacity promoted the retention of soil organic carbon in surface soil. (3) Redundancy analysis results showed that soil properties explained 65.50% of the changes in soil organic carbon mineralization characteristics, and SOC, MBC, DOC and Ca²⁺ were important soil factors in regulating soil organic carbon mineralization. The community structure of bacteria and fungi explained 66.50% and 19.80% of the changes in soil organic carbon mineralization characteristics, respectively. Moreover, Bacteroidetes, Actinobacteria and Mortierella were the main microbial groups regulating soil organic carbon mineralization. However, diversity of bacteria and fungi had no significant effect on the changes of soil organic carbon mineralization characteristics. In summary, land use types resulted in the changes in soil carbon substrates and Ca²⁺ content, which affected microbial community structure, especially, some specific microbial phyla, thereby regulating soil organic carbon mineralization.