A network signal coupling and EMI protection circuit assembly includes a processing circuit installed in a circuit board and coupled between a voltage-mode network-on-chip at the circuit board and a network connector and drivable by a driving voltage outputted by the voltage-mode network-on-chip to process network signals. The processing circuit includes opposing first connection end and second connection end, two-wire channels electrically connected between the first connection end and the second connection end, a coupling module and an EMI protection module installed in each two-wire channel for coupling network signals and removing noises. Each EMI protection module includes two inductors respectively installed in the two wires of the respective two-wire channel and two capacitors connected in series between the two wires of the respective two-wire channel and grounded for filtering resonant waves in low frequency as well as high frequency to prevent electromagnetic interference and to enhance signal transmission stability.