Electromagnetic field anti-fouling technology has received great attention because of its advantages of low investment, zero pollution,etc. Reasonable selection of electromagnetic parameter is one of the necessary conditions for the best result of electromagnetic anti-scaling. This research designed a set of dynamic electromagnetic experiment with electrical conductivity method. The characteristics of varying conductivity with time in the titration process under the given experimental conditions were compared, and the calcium carbonate crystallization metastable curve under different solution concentration and intensity of the electromagnetic field were obtained. Then, the influence of electromagnetic field on the induction period of calcium carbonate precipitation from the perspective of the metastable zone was analyzed. Finally, it was found that the 200 Gs was the best magnetic field intensity values of electromagnetic fields inhibiting calcium carbonate crystallization.