Abstract: The foreland thrust belt has complex and various structural styles. Besides the large-scale reverse faults, there are a series of north-west strike-slip faults. Based on high-resolution seismic data, the foreland fault systems in the NW margin of Junggar basin were analyzed. It reveals that the strike-slip fault system of Ke-Bai area can be divided into two types, namely the flower strike-slip faults and the simple strike-slip faults, which have obvious differences in genesis and section features.The strike-slip faults have dual influence on hydrocarbon migration and accumulation. They can not only be effective migration channels for petroleum, but also can seal petroleum.