It is difficult to obtain credible results from the study on the depositional system in sparse-borehole areas. The advanced 3D seismic information is used in the study on detailed depositional system. Based on the regional depositional settings and single well sedimentary microfacies, we apply spectral decomposition data to analyze the sand distribution in the area of about 400 km², use amplitude slice, waveform analogue slice and reflection section to confirm the main stream channels, and use waveform analogue slice to determine the sedimentary boundary. The groupⅠ in the second member of Sangonghe Formation in the central Junggar Basin is divided into two depositional systems and four stream channels, which provides foundation for the interpretation of the lithologic traps in the study area.