The discovery of Renli ultra-large tantalum—niobium deposit in Mufushan area, northeastern Hunan Province, provides a new research idea for finding pegmatite-type rare metal deposits. The study shows that northeastern Hunan is an important metallogenic area of niobium—tantalum—lithium—beryllium rare metal deposits. The project carried out remote sensing—geophysics—geochemical exploration—X-ray fluorescence—geogas analysis comprehensive exploration research in the western prospecting area of Renli mining area, in order to establish an efficient and rapid prospecting technology and method system for pegmatite rare metal deposits in high vegetation coverage areas in the South. In this study, X-ray fluorescence exploration technology was used to measure the soil samples of 153 measuring points in 3 survey lines with a total length of 3000 m in the working area. The contents of Nb, Ta, Rb and other important metallogenic elements were obtained at each measuring point. Through the analysis of the characteristics of ore-induced X-ray fluorescence anomaly, the nature of the anomaly in the working area is determined. Compared with the obtained exploration results, it is in good agreement, and it is speculated that there may be an unproven pegmatite vein of niobium—tantalum ore on a survey line, which provides basis for subsequent exploration engineering work. It also shows that X-ray fluorescence exploration method has good prospecting effect and can provide reference and indication for prospecting.