Abstract: Using 3D seismic data combined with logging and drilling data，the paleogeomorphology of the Triassic Baikouquan Formation in Shixi area of the Junggar Basin was reconstructed using sedimentary paleogeomorphology restoration techniques. Based on the clarified planar distribution characteristics of sedimentary facies，the relationship between paleogeomorphology and sedimentary facies was explored，and favorable areas for oil and gas exploration were identified. The research results show that：（1）The steps for restoring ancient landforms include calculating the thickness of the strata in the time domain，calculating the thickness of the strata in the depth domain，recovering denudation thickness of the strata，decompaction correction，and restoring the ancient water depth. During the deposition of the Baikouquan Formation，Shixi area exhibited a "northwest high，southeast low" structural pattern. The northwest was characterized by a large highland，while the central and eastern parts developed uplifts and six primary troughs，which interwove with each other. The southern part contained three depressions. The paleogeomorphology was primarily a combination of uplifts，troughs，and depressions.（2）In the northern and central parts of the study area，a braided river delta plain subfacies was predominantly developed，characterized mainly by distributary channel microfacies，segmented by interdistributary bay microfacies. In the southwestern and western regions，a braided river delta front subfacies dominated，including underwater distributary channel and interdistributary channel microfacies，with localized development of mouth bar and sheet sand microfacies.（3）The paleogeomorphology in the study area controlled the distribution of sedimentary facies. The shape and characteristics of the paleogeomorphology directly influenced sediment sources，transportation pathways，and depositional environments. Specifically，sediment from the northeastern source was transported through delta sand bodies to the southwestern lake basin center，with six paleotroughs serving as primary transportation channels and restricting frequent channel migrations. Strong hydrodynamics in the troughs resulted in thick，multi-period stacked distributary channel sand bodies. In uplift areas，river channels had minimal influence，allowing for the accumulation of thick mudstone，with interdistributary bay microfacies development. In depressions，where channels expanded，hydrodynamics weakened，resulting in fine sandy deposits and the development of extensive sheet sand microfacies.（4）The eastern trough area and southern depressions in the study area are favorable zones for reservoir development and key exploration targets.

Key words: paleogeomorphology restoration, braided river delta, sheet sand, distributary channel, decompaction correction, Baikouquan Formation, Triassic, Shixi area, Junggar Basin