In view of the need of the electromagnetic compatibility analysis in the design process of the electronic equipment, an equivalent method of modeling the characteristics of electromagnetic radiation from printed circuit board interference source is proposed by using magnetic dipole array. According to the characteristics of the electromagnetic boundary value problems, the radiating source and the structures affecting the radiation are modeled separately. At first, the actual source is modeled in detail. Then the effect of surrounding structures on the overall radiation is incorporated into the model. Moreover, the basic ideas of equivalent modeling are introduced, and the derivation of the formulas to obtain the magnetic dipole array is given. Finally, a patch antenna is used to demonstrate the validity of the method. The results show that the equivalent modeling method significantly reduces the complexity of the model, the modeling time, and the computational burden.