Determining the difference in arrival time between direct waves and reflected waves in the Loran-C signal is crucial for effectively using it for ranging.Based on the analysis of waveform characteristics of the measured waves and theoretical waves in Loran-C signal, it is considered that the direct wave signal included in the measured Loran-C signal is consistent with that in the theoretical signal.Therefore, the theoretical direct wave signal can be removed from the measured Loran-C signal via waveform subtraction, then the difference in arrival time between direct waves and reflected waves can be calculated by using cross-correlation method.