Abstract: Thin-layer carbonate rocks often contain more argillaceous interlayers, and more shallow karst fissures were formed, which may affect the stability of engineering foundation. However, there are few studies on the characteristics and occurrence of karst development in thin-layer limestones, which cannot effectively guide the exploration and design of engineering activities. In order to explore the characteristics of shallow karst development in thin limestones, based on the results of shallow karst investigation on a road in the Heihe mining area near the city of Heshan in Guangxi, the macroscopic and vertical distribution characteristics of thin layer limestone karst are analyzed. According to the degree of dissolution, it is divided into the clastic residual zone, surface karst zone and lower aeration zone. The dissolution process under the influence of mineral composition, CO2 and hydrodynamic conditions is analyzed by the indoor dissolution test. The thin-layer and thick-layer karst development characteristics are compared and analyzed. The results show that (1) the degree of karst development in the shallow layer of limestone is related to the micro-geomorphology, which is usually more intense in the valley and strong groundwater runoff zone. (2) The karst erosion of thin limestone begins preferentially with calcite, forming karst holes and increasing roughness on the surface of rock, which provides corrosive solution flow channels. (3) The karst of thin limestones is smaller in scale and more uniform in distribution, and the groundwater infiltrated into underground rock mass by surface soil contains more erosive CO2 aqueous solution, which will promote the development of karstification. (4) The evenly developed micro-cavitation cracks will expand horizontally in the process of dissolution and infiltration, and will be filled with further dissolution. The dissolution will gradually dissipate in the vertical deep development. Understanding the karst development characteristics and distribution model of shallow limestone in shallow rocks is of a guiding value for the difference in the accuracy of engineering survey work and the selection of basic engineering for the same type of karst site in different regions.