Fengcheng Formation of the Lower Permian in Junggar Basin is a set of important source rocks. The understanding of the sedimentary environment in this period is controversial in that it is understood as marine facies by some researchers and as lacustrine facies by others. This paper utilizes the outcrop，seismic，drilling，logging，and core data in the study area and its adjacent areas to identify the formation period of Bogda Mountains at the southern margin of Junggar Basin and the geological structures in the basin，restores the tectono-sedimentary framework of the Early Permian in Junggar Basin，and analyzes the petroleum geological characteristics of Fengcheng Formation. The results show that the East Bogda Mountains and the east margin of Eren Habirga Mountains separated Junggar Basin from Tuha Basin，and Junggar Basin became a lake with marine vestiges due to residual sea occlusion at the end of the Carboniferous. Shixi Sag in the north of the basin and Shiqiantan Sag mainly developed the alluvial fans during the sedimentation of Fengcheng Formation. The northwestern margin，the central depression，and Bogda area，as lakes with marine vestiges in terms of sedimentary environments，inherited the marine saline water environment and marine organisms. Four sedimentary centers were developed in the basin，and favorable source rocks were developed in the semi-deep to deep lacustrine subfacies in saline water environments under the control of the uplifts and underwater low upheavals in Junggar Basin. The various sags in the hinterland of Junggar Basin and the periphery of Bogda Mountains，where the Lower Permian is widely distributed and incredibly rich natural gas resources might exist in deep burial environments，are favorable exploration directions for the next step.