Abstract: There are a good number of hot springs in the west of Yunnan province. From the distribution of hot springs in the whole country, Baoshan is located in hydrothermal activity dense zone of "South Tibet-West Sichuan-West Yunnan". Baoshan basin is a typical fault depression basin formed by geological structure, and the hot springs distributed in the basin are mostly exposed along the fault edge of the basin. In the upper part of the basin, the tertiary and quaternary low thermal conductivity deposits with a thickness of several hundred meters to nearly one kilometer form a geothermal good cover. Its bottom is just located in the area of high geothermal heat flow so that the large fault at the edge of the basin brings the deep crustal hot water to the basement of the basin by convection through the fault. With good cover, the heat loss of basement groundwater is small, and the underground hot water can be exploited after the borehole is uncovered. Through the research on the formation mechanism of Hanzhuang hot spring in Baoshan, this paper explores the formation mechanism of geothermal in Baoshan Basin in order to provide reference for the development and utilization of geothermal in Yunnan and even the whole country.