Abstract: The traditional underwater acoustic modeling methods only consider the influence of the refraction of sound waves in the water and ignore the acoustic reflection between the water layers, therefore the imaging results of seawater layered structure in the reflection seismology cannot be analyzed. A sound propagation model of low-frequency broadband pulse based on time-domain finite-difference is established in this paper. This model takes the acoustic reflection effects of the seawater layered structure into account, and the time-domain waveform of the low-frequency broadband signal in the process of short-distance propagation is calculated by numerically solving the wave equation. Then, by considering the hydrological conditions of a maritime multi-channel seismic survey as the input environmental parameters, the air-gun signal waveforms received by the near sea-surface receiving arrays in seismic exploration are simulated. Finally, according to the processing procedure of reflection seismology, the received array signals at the co-reflection points are sorted for coherent accumulation and seismic imaging. The obtained imaging result of seawater layered structure is in good agreement with that of the marine multi-channel survey, which validates the effect of the acoustic reflection of water layer on seismic imaging of the reflection waves of seawater layered structure.