As an important terrestrial environmental proxy index, the formation and evolution of pedogenic carbonate is controlled by multiple environmental factors, including climate, topography, parent material, biology and time. This paper first introduces the composition, classification, formation mechanism and environmental factors of pedogenic carbonate. Subsequently, it focuses on their C-O isotopic composition, applications in paleoenvironmental reconstruction, and advances in chronology. Studies have shown that the C-O isotopic signatures of pedogenic carbonate are primarily controlled by key parameters such as soil-respired CO? concentration, soil water and soil temperature, providing reliable foundation for the quantitative reconstruction of paleoatmospheric CO? levels, paleo-C3/C4 biomass and paleoprecipitation, paleotemperature, paleoelevation. Geochronological methods such as uranium-series dating further furnish precise temporal framework for the paleoenvironmental reconstruction. However, challenges persist due to the complexity of pedogenic processes, including pedogenic carbonate spatiotemporal heterogeneity, diagenetic overprinting and selective preservation of environmental signals. Finally, this review outlines future research directions and development trends for pedogenic carbonate in the paleoenvironmental reconstruction field.