The Xiangshan uranium orefield in Jiangxi Province is one of the largest volcanic-related uranium orefields in China. The Penggushan district is located in the western part of the Xiangshan uranium orefield, close to the Julongan and Zoujiashan large uranium deposits, and has favorable minerogenetic conditions. In recent years, a significant breakthrough in the exploration of uranium deposits has been made in the Penggushan area, where the hydrothermal alterations are high-temperature alteration with less later superimposed alteration, so it is an ideal place to study the relationship between high-temperature hydrothermal alteration and uranium mineralization. In view of this, on the basis of a field geological survey, this paper analyzes the geochemical characteristics of hydrothermal alteration in Penggushan area through petrographic and whole rock geochemical analysis and discusses the characteristics of high-temperature hydrothermal alteration and its relationship with uranium mineralization. The results show that the high-temperature hydrothermal alterations are commonly dominated by albitization, desilication, chloritization, and illytization, and locally overprinted by apatitization, pyritization, carbonation, and silicification. The uranium mineralization shows a close spatial relationship with the albitization, apatitization, carbonation, and desilication. In the Penggushan district, uranium mineralization is alkali-metasomatized and formed in a medium-high temperature reductive environment. The occurrence of apatite in fluid is possibly an important factor for the formation of high-grade mineralization in the study area. Apatitization and carbonation superimposed on alkali metasomatic alteration are most strongly developed in the ore body, which are regarded as the most important prospecting indicators in future uranium resource exploration of Penggushan area.