A blind channel estimation algorithm is proposed in this paper by analyzing the received signal of uplink for MC-CDMA system. The proposed algorithm uses the second order statistics of the received signal and the user spreading sequences to separate the user information and to estimate the channel response. Then PIC technique is used to improve the performance of the algorithm. The proposed algorithm has nothing to do with the type of noise. And the results of computer simulation show the proposed algorithm has excellent performance in wireless channel.