Orthogonal Frequency Division Multiplexing (OFDM) technique is an efficient data transmission technique with good immunity for the effects of multi-path channel interference, inter-symbol interference, narrowband interference and high frequency spectrum utilization ratio. It has been widely used in practice. Automatic identification and modulated parameter estimation of communication signal of OFDM are key technologies in non-cooperative communication and software radio. Aiming at the detection methods of OFDM signal based on higher order cumulants, the paper proposes a novel method used to detect OFDM signal in the fading channel based on four higher order moments. This method can detect OFDM from signal-carrier modulated signals (MPSK or MQAM) .Theory analysis and simulation date can prove that the algorithm has beautiful detection and identification defection and fading signal adaptability.