In order to improve the disaster prevention and mitigation capacity of regional geologic disasters in karst mountainous areas, taking Meitan county in Guizhou province as an example, regarding landslides and avalanches of geologic disaster sites in the county as the research object, by using spatial analysis function of ArcGIS software, development law, distribution characteristics and influencing factors of geological disasters have been analyzed. Combining with the characteristics of geologic environmental conditions in the area, pregnancy disaster conditions of regional geological environment are evaluated and divided. It is showed that there are many factors influencing geologic conditions of pregnancy disaster. The internal factors are regional slope, slope height, stratigraphic lithology, slope structure, geologic structure, structural surface yield, and weak strata, and external factors are atmospheric precipitation and human engineering activities. Pregnant disasters with high index in Meitan county are mainly located in the central and northern areas, and most of them are in the form of a band, which has a high possibility of geologic disasters in a short period of time.