The channel estimation based on compressed sensing (CS) technology is applied in the OFDM system to improve the spectrum utilization. However, the traditional timedomain sampling method causes the imprecision to the channel measurement matrix, which can’t accurately recover the channel state information of the transmission channel path. To solve this problem, a fractional delay channel model is proposed to simulate the system wireless multipath channel, and a timedomain oversampling at the receiver is exploited to improve the estimation accuracy. Meanwhile, to reduce the computational complexity for which is increased due to the timedomain oversampling, a modified orthogonal matching pursuit (MOMP) algorithm is proposed to lower the computational complexity. The simulation experiment results show that the timedomain oversampling at the receiver proposed in this paper can accurately detect the channel fractional delay and the proposed MOMP algorithm can significantly reduce the computational complexity of the estimation algorithm under the fractional delay channel environment.