Single-side-band power line carrier equipment usually uses the modulating method of frequency shift keying（FSK） to implement tele-control signal transmission， in which the transmission rate exceeds neither 600 bit/s in the speech and tele-contol simultaneous multipurpose mode nor 1 200 bit/s in the tele-control single-purpose mode. To increase the tele-control signal transmission rate， this paper proposes a new transmission method based on the multi-carrier modulation（MCM） scheme. The transmission principle is to convert a serial data stream into a coded parallel data stream， insert a frame synchronization sequence into a data stream and map it， then modulate the data stream by the inverse discrete Fourier transform（IDFT）. In the reverse direction， the input multi-carrier signal is sampled， demodulated by the discrete Fourier transform（DFT） and the inverse signal mapping， then the frame synchronization sequence is removed and decoded， till finally restoring the original data using parallel-to-serial conversion.