The heat island effect, as the thermodynamic performance of the artificial ecosystem established by human modification of the natural environment matrix, should be studied from the comprehensive perspective of the regional thermal environment. Jianshui-Kaiyuan-Gejiu-Mengzi of Honghe Prefecture, as one of the regions with the most concentrated and complex ecological problem in Yunnan karst rocky desertification areas, can be coupled with urban heat island, dryhot valley and karst rocky desertification for the comprehensive study, which has practical significance for the construction and restoration of the regional ecological environment. Based on the overall analysis of the karst rocky desertification and regional thermal environment in Southern Yunnan, it used the spatial interaction supported by a long time series of remote sensing images to study the influence of impervious surface, land use, vegetation coverage and rocky desertification degree on the regional thermal environment, so as to support the construction of human settlements in the karst rocky desertification areas, especially the construction of thermal comfort. The results showed the following: While the heat island was mainly distributed in the dam areas, but scattered in the surrounding mountain areas, the area was basically maintained at about 3000.00 km 2 , accounting for 1/4 -1/3 of the whole study area. The total net increase of impervious surface in the past 30 years was 204.98 km 2 , while the proportion of impervious surface forming heat island showed an overall rising trend, from 44.17% in 1990 to 62.63% in 2020. The land use covered by the heat island was mainly cropland, as it showed an increasing trend, maintaining above 50.00% from 1990 to 2005 and above 60.00% from 2010 to 2020. The vegetation coverage covered by the heat island was mainly medium to low/medium vegetation coverage, as the total net increase in the past 30 years was 1801.72 km 2 , with the proportion above 60.00%. The rocky desertification covered by the heat island was mainly extremely severe rocky desertification (Fr > 0.90), as the total net increase in the past 30 years was 1526.60 km 2 , with the proportion above 40.00% gradually. Based on the regional thermal environment, the finding not only focuses on urban heat island and karst rocky desertification, but also provides theoretical support for the interpretation of the dry -hot valley's formation.