Abstract: The kinematic characteristics and dynamic mechanisms of key faults in the Yinggehai Basin and the Red River Fault Zone remain controversial. This study applies stratigraphic backstripping and balanced cross-section restoration to quantify subsidence and extensional rates of major faults in the Yinggehai Basin across different geological periods, aiming to clarify the tectonic activity of the Red River Fault Zone and the basin's evolutionary history.Results show that between 30 and 21 Ma, strike-slip faulting was primarily concentrated along the Song Lo Fault, while horizontal extension remained relatively minor. During this period, significant extensional deformation was localized in the Chay Fault zone. The main subsidence center was located in the Hanoi Depression, especially in the overlap zone of the Chay Fault, Thai Binh Fault, and east-west trending fault systems. From 21 to 15.5 Ma, tectonic inversion occurred in the northern basin, with the most intense compressional uplift centered on the Lingao Uplift. Concurrently, the Song Lo, Yingdong, and Dongfang Faults experienced varying degrees of tectonic inversion.The tectonic behavior of the Song Lo Fault mirrors that of the Red River Fault Zone, with the Yingdong and Dongfang Faults acting as southern extensions of the Song Lo Fault within the Yinggehai Basin. The escape tectonics of the Indochina Block was marked by substantial regional extension, with strike-slip deformation occurring along boundary faults on the eastern margin of the Yinggehai Basin, while extensional tectonics was widespread both within and around the basin. The observed tectonic inversion is closely linked to the reduction of left-lateral shear along onshore faults and the cessation of rotational motion of the Indochina Block.