At present there are several methods to do EMI measurements in GTEM cell, such as EDM, MDM, Linear, Wilsonpsilas method and so on. But the difference between the calculated results of these methods and the EMI results measured in OATS (open area test site) is very large in some situation. This article provides a new method to calculate electric field intensity in GTEM cell using the equivalent dipole of the radiator. And series of experiments were performed to prove the validity and advantage of this method. The experiment results show that the calculated results of new method is more agree with the measured results in OATS, which means that the new method can be considered as a more approached way to calculate the electric field intensity in GTEM cell for EMI measurements.