The critical metals ore bed, characterized by its enrichment in Nb, Zr, REY, and Ga, is situated at the bottom of the Upper Permian coal measures in eastern Yunnan- western Guizhou, China. This ore bed, with a consistent thickness of several meters and a distinctive positive anomaly in natural gamma- ray data, represents a significant potential resource of critical metals. Previous research on these ore beds mainly focuses on the sources of ore- forming materials, critical metal hosts, and metallogenic models. However, the identification and quantitative calculation of critical metal concentration in these ore beds using logging data remains unexplored, despite the crucial role this analysis plays in guiding future exploration and development of critical metals. Focusing on Zr and Ga as representative elements, we developed concentration prediction models using comprehensive datasets comprising critical metal concentrations and corresponding natural gamma- ray values. The models for Zr and Ga are represented by the equations: y=133. 42x2+262. 23x+224. 43 for Zr and y=31. 587 e0. 2273x for Ga. These models were then utilized to determine the natural gamma- ray values corresponding to the minimum exploitation concentrations of 2000 μg/g for Zr and 50 μg/g for Ga, yielding values of 2. 8 pA/kg and 2. 0 pA/kg, respectively. The predicted boundary of the ore bed, obtained through a 3- order decomposition of the Haar wavelet, exhibits a strong correlation with the geochemically determined boundary. Validation of these models demonstrates their efficacy in predicting critical metal concentrations and ore bed thickness. Average relative errors in concentration prediction were found to be 14. 21% for Zr and 10. 97% for Ga. Similarly, average relative errors in ore bed thickness prediction for Zr and Ga were 4. 16% and 4. 82%, respectively. These findings underscore the accuracy and potential of this fine exploration technology in accurately predicting critical metal concentrations and ore bed thickness, thereby offering significant promise for future exploration and development of critical metal resources in the study area.