Abstract: In order to analyze the three-dimensional distribution law of Ordovician limestone in Xiaoyun Coalfield, based on the evolutionary regularity of tectonic stress in the study area, we reveal the development mechanism of Ordovician limestone karst with the help of statistical analysis and physical chemistry experience. First, according to the fractal theory, X-ray diffraction experiment and Glass slide qualification test, we analyze the complexity of fault structure, mineral component of rocks and development degree of fissures. Second, by means of water quality analysis, we calculate the Laagelier saturation index（Ｌ．Ｓ．Ｉ．）, Ryzner stability index（Ｒ．Ｓ．Ｉ．）, and precipitation index（Ｐ．Ｓ．Ｉ．） of water samples in the study area, and analyze the stability of karst aquifer. Finally, we conclude the development law of karst with the help of zone map of tectonic complexity, mineral component and results of water analysis experience. According to the study, influenced by faults, the development level in the central and western of the study area is higher horizontally, and the most appropriate location for karst development in the study area is 40-80 m away from the top interface of Ordovician limestone vertically. However, it is less likely that the karst fissure will continue to develop due to the higher saturation of Ordovician limestone water in study area.