Exemplified by the Zhangxian salt district, this paper points out the advantages of applying the logging method to locating the rock and mineral bed. According to the electric character and radioactivity of the strata as well as their relationship, the binary regression method was used to obtain the theoretical equation for the salt mine district. The result of applying the empirical equation to salt mine grade interpretation is also given. Tests show that the application of the regression method to qualitative and quantitative interpretation is feasible. For the rock salt bed which can meet the related conditions, the utilization of this method can yield fairly ideal geological result, which has practical guiding significance in salt field evaluation.