Based on the interpretation of the seismic profiles in the middle Jizhong depression, it is pointed out that the area underwent three types of extension since the mid-Mesozoic, that is, heat doming extension, stress extension and gravity extension. The heat doming extension related with the Fuping nuclear complex took place in the Taihang Mountains in the middle-late Mesozoic. Doming of the nuclear complex lead to lateral extension and detachment faults were developed on the east margin of the Taihangshan Mountains to form a contemporaneous down-faulted basin (Baoding depression) in the foot wall. It is well known that the Bohai Bay Basin came into a stress extension stage in the Eogene, during which the detachment fault and normal fault are two types of growing faults. The former dips gently in shallow layers, but steeply in deep layers of the crust and becomes a horizontal ductile shear zone at the bottom, expressing strongly horizontal extension, whereas the latter has a small extension. A large-scale detachment structure was distinguished in the south area of the Raoyang depression. It is bounded by the Cangxi fault in the east, the Lixian slop in the west, the north Liulu fault in the north and the Hengshui fault in the south. The area is near 2000 km2. This took place due to gravity gliding after the unbalanced uplifting of the Cangxian bulge at the end of the Eogene. This structure is characterized by clear detachment faults, two different deformation systems, as well as the front edge and back edge. The gliding track in the area is like a crawl tract of insects. This is a new gravity gliding model. The three types of extensional structures are connected to each other, influence each other, and there are clear coupling relationships between basins and mountains.