Performance of traditional adaptive line enhancer (ALE) in suppressing Gaussian noise is low and can get worse at low input signaltonoise ratio(SNR). For greatly overcoming these disadvantages, feature of fourthorder cumulant(FOC) different slices for quasistationary random process is analyzed, fourth order cumulant(FOC) different slicebased adaptive dynamic line enhancer is presented, and output SNR of the proposed enhancer is derived and bigger than that of the ALE via theoretical analysis. Simulation tests with the underwater moving targetradiated data have shown that the proposed enhancer outperforms the ALE in suppressing Gaussian noise and enhancing dynamic line spectrum feature. For greatly over these disadvantages, feature of fourthorder cumulant (FOC) different slices for quasistationary random process is analyzed, fourth order cumulant (FOC) different slicebased adaptive dynamic line enhancer is presented, and output SNR of the proposed enhancer is derived and bigger than that of the ALE via theoretical analysis. Simulation tests with the underwater moving targetradiated data have shown that the proposed enhancer outperforms the ALE in suppressing Gaussian noise and enhancing dynamic line spectrum feature.