Objectives: Xiakou fault zone is a boundary fault in the south of Linnan sag, which controls stratum distribution and hydrocarbon migration. However, its genetic mechanism is still unclear. Methods: Based on abundant 3D seismic data, analysis of the geometric and growth process of the Xiakou fault zone, the segmentation and periodicity of its development and evolution are revealed and discuss the genetic mechanism. Results: The results show that Xiakou fault zone is a serrated fault zone and formed by the four segments connecting the NE strike and the EW direction alternately. The evolution process can be divided into four stages under the control of the regional geological. Ek stage only have NE- trending segments activities(first, third(western) and fourth), and the EW- trending (second and third(eastern))has not developed. The Xiakou fault zone is in independent growth stage. Es4 stage with the transformation of regional stress from NW—SE to near S—N, NEtrending segments continue activity and EW- trending fault start activity. Soft connection happend between NE- trending segments. Es3 stage under the strong tensile action of S—N direction, hard connection occurred in the Xiakou fault zone.The segmented faults in different directions are connected to a whole, forming a serrated fault zone that occurs alternately between NE- trending and EW- trending. Es2—Ed is the stage of strike- slip transformation. Broom structures and strike- slip duplex developed in different positions. And produce local tension or extrusion on the different bending segments. It reflects the superposition effect of strike- slip under extension background. Conclusions: The spatial and temporal difference of the development and evolution of the Xiakou fault zone has an important control effect on the distribution of the settlement center and the source channel in this area.