The invention discloses a narrowband power line communication power-frequency zero transmission method based on OFDM modulation, comprising the following steps: confirming an original message needing to be processed and sent by a physical layer; forming a frame message; judging whether or not to send the frame message according to a power-frequency zero transmission mode; configuring the format of the frame message; regularly sending the configured frame message; sending the frame message according to a continuous transmission mode in the original G3-PLC standard; regularly sending the configured frame message; judging whether or not to receive the frame message according to the power-frequency zero transmission mode; demodulating the received data according to OFDM demodulation and FEC decoding modes in the G3-PLC standard; demodulating the received data according to OFDM demodulation and FEC decoding modes in the G3-PLC standard; and obtaining a receiving-end demodulation message, and completing receiving and processing tasks of the physical layer. The method of the invention ensures high communication rate while being compatible with international standards.