A noise filtering circuit for suppressing electromagnetic interference (EMI) is provided. The noise filtering circuit filters out high multiplied-frequency noise of a digital signal being transmitted and includes a reference voltage structure formed from conductors, a signal transmitting structure formed from a transmission conductor, a ground layer, and a ground structure electrically connected to the reference voltage structure and the ground layer. The ground structure is configured to form an inductor-capacitor oscillating structure in coordination with the electric-magnetical coupling between the reference voltage structure and the signal transmitting structure as well as the inductance of the ground structure, so that a digital signal is filtered out at a specific frequency and the passband of the digital signal can be transmitted.