The invention discloses that based on open IFFT / FFT lower reserved subcarrier OFDM system PAPR methods and devices, and the system is using IFFT / FFT transform to a peak frequency domain Consumers sequence in the transmitter to reduce OFDM system ratio of power PAPR, the method described in steps including data distribution , IFFT transformation, realizing OFDM modulation, gained time-domain signal, judgment threshold and whether the number of iterations is to achieve settings, limited Consumers peak processing, extracted through FFT frequency domain reduce-peak sequence. The installations include the transmitter and receiver, the transmitter unit increased data distribution, data option modules, judgment unit, a unit reduce-peak sequence, sequence reduce-peak insert modules; Receiver increased information extraction unit. This invention in a process of elimination-series will not lead to the increase in bit error rate, the effect of significantly reducing the PAPR, the device is simple, running FFT / IFFT the iteration times is less.