For the purpose of accurate judgment of the rock salt horizon in a certain ore district and meeting the requirement of reserve calculation, geophysical well logging method was adopted in rock salt exploration. Practice shows that the well logging method can accurately divide lithologic characters and make up the shortcomings of drill coring. In combination with the analytical results of rock salt samples, the regression analysis theory can be used to obtain the relationship between the rock salt grade and the radioactive intensity and predict the industrial grade of the rock salt. The results obtained by the authors demonstrate that the utilization of the regression analysis to predict the industrial grade of the salt rock is feasible, and the predicted result can meet the requirement of field production and provide useful information for rock salt exploration.