Abstract: The Yonghan Geothermal Field is located in Yonghan Town, Longmen County, Guangdong Province. It is divided into two thermal anomaly areas, Maxing and Gebei. Through geological survey, geo⁃ physical exploration, geothermal drilling, depressurization test and temperature measurement, the geother⁃ mal geological conditions of the Yonghan geothermal field were basically identified. It is calculated that the geothermal resource reserve of Yonghan geothermal field is 9 925 m³/d, and the average water temperature is 57.8 °C.The concentration of metasilicic acid and fluorine in the geothermal water resources of the local hot field reaches the standard of named mineral water concentration, which can be named as silicon water and fluorine water, and has medical value. It is proposed that the development and utilization direction of geothermal resources in this geothermal field is mainly hot spring physiotherapy and bathing. The design, production and construction scale is 8 932 m³/d, and the service life is tentatively set as 10 a. The scope of the three-level protection zone of the local geothermal field is delineated, which provides a geological basis for the development and utilization of geothermal resources and the protection of geological environment.

Key words: geothermal field, geothermal geological conditions, resource reserve calculation, geother? mal development