Based on variation of water quality parameters under the influence of frequency conversion electromagnetic field，the relationship between conductivity，pH value and magnetic acting time was analyzed by using the correlative degree analysis and balanced adjacent degree.The results of Origin and Matlab showed that the relevance of conductivity and magnetic acting time was better than pH value.Compared with pH value，conductivity was more suitable for constructing the mathematical model of electromagnetic field and water quality parameters and was more closely associated with electromagnetic field than pH value in the process of fouling formation.This method provided the theoretical and experimental basis for the suitable selection of mathematical model of electromagnetic parameters and water quality parameters.