A novel blind time-frequency joint synchronization based on the cyclostationary of orthogonal frequency division multiplexing with offset quadrature amplitude modulation (OFDM/OQAM) systems is conceived in multipath channels conditions. The cyclic cumulants of OFDM/OQAM signals are derived firstly, symbol timing offset (STO) and carrier frequency offset (CFO) are estimated by employing two groups of different even cycle frequency. The simulation results demonstrate that the proposed method is robust to noise and multipath channels conditions without any requirements of a prior knowledge in non-cooperative communications.