Soil improvement plays a critical role in enhancing the soil carbon sink capacity and optimizing karst processes under global climate change. Using bibliometric methods, this study analyzed literature from Chinese and English journals (1990-2024), focusing on the regulatory mechanisms linking soil improvement to soil carbon cycling and karst carbon sinks. The Web of Science (WoS) and China National Knowledge Infrastructure (CNKI) databases indexed 712 and 468 relevant articles, respectively, most of them original research papers. Article numbers showing a fluctuating upward trend over the 34 years. This process can be divided into three phases: germination (before 2005), growth phase (2005-2013), and rapid development (after 2013). English-language journals published more articles than Chinese-language journals. The English-language literature initially focused on biochar carbon sequestration mechanisms and greenhouse gas emissions. Over time, the focus shifted towards the synergistic regulation of soil microbial functional genes and nitrogen-phosphorus nutrient cycling, reflecting a transition from mechanism-based analysis to application-oriented microbial-nutrient coupling. Chinese-language literature has expanded from monitoring basic indicators, such as soil respiration, moisture, and heavy metals, to systematic research on soil aggregate regulation, microbial community optimization, and improvement techniques. In addition, a Carbon-Pool Management Index (CPMI) is established to guide practical applications. In low-productivity karst regions, soil improvement efforts primarily assesses improvement measures on karst processes and the soil carbon balance. This study explored the bidirectional coupling relationship between karst carbon sinks and soil improvement. Specifically, high concentrations of soil CO₂ drive carbonate rock weathering, whereas improvement measures enhance the carbon sink effect by improving soil quality. To advance soil improvement research in karst areas, it is recommended to establish a quantification method for measuring the increase in karst carbon sinks due to soil improvement and develop a database. Furthermore, considering the calcium-rich and alkaline characteristics of karst soils, the synergistic effects of improvement measures on ecological restoration and sustainable agricultural should be evaluated to provide scientific support for global carbon neutrality. By leveraging soil improvement technologies, we can enhance soil and karst carbon sinks, address climate change more effectively, promote the integration of ecological restoration and sustainable agricultural development in karst regions, and contribute to the achievement of China’s Dual Carbon Goals.