<p>Rock outcrops are common features of the karst ecosystem The bare rock rate is an important indicator for rocky desertification grades classification, and its accurate extraction can benefit for understanding the distribution characteristics of rock outcrops in desertification areas and the classification of rocky desertification grades. In order to explore the distribution pattern of surface bare rocks in the typical geomorphic environment of the Karst gabin basin, the Mengzi gabin basin was carried out as the research site. The combination of UAV shooting images and digital image processing technology were used, the characteristics of bare rock rate on the karst fault basin after vegetation restoration were shaped. Our results showed that digital image processing technology can be used for extraction of bare rock rate in Karst area, and the effective combination of UAV technology and digital image processing technology can quickly obtain bare rock rate data of typical landform in Karst gabin basins. After performing drone aerial photography on 26 typical landform information under different bare rock distribution conditions on the Mengzi gabin basin, the results of the image processing analysis showed that the bare rock rate is between 2.7%-28.9%. The research provide technical support for the assessment of the karst ecosystem degradation and the evaluation of the current status of rocky desertification in karst gabin basin</p>