The invention relates to an electromagnetic interference detecting device which is used for detecting a noise signal of a noise signal source and comprises a detector, a signal receiver and a signal display unit, wherein the detector is used for being in single point contact with the noise signal source and switching the noise signal into a wireless signal with respect to the noise signal, the signal receiver is used for receiving the wireless signal emitted from the detector, the signal display unit is used for displaying the wireless signal transferred from the signal receiver, and the signal receiver is electrically connected with the signal display unit. The detector comprises an insulating rod, a probe and a conducting wire, the conducting wire is wound to the other end from one end of the insulating rod spirally, and the probe is connected with one end of the conducting wire and extends away from the insulating rod from one end of the insulating rod.