Abstract: The Baiyun deep water area (including Baiyun depression and Liwan depression) in the Pearl River Mouth Basin is located on the continental margin crust thinning zone in the northern South China Sea. The thickness of the crust is rapidly reduced from 29 km on the north side to 17-18 km. Due to the strong extension and thinning of the crustal lithosphere, the deep water area at the continental margin is characterized with special fracture structure and sedimentation characteristics, which has an important control effect on the sedimentary system and leads to differences in the characteristics of hydrocarbon play in the deep water area. By investigating the extension and rupture process of the global typical extensional continental margin basin and the control of fault structure pattern on sedimentary system, a coupling analysis was conducted between the depression structure, fault structure pattern, tectonic subsidence history and sedimentary system in the Baiyun deep water area, revealing the response characteristics and developmental mechanisms of special sedimentary systems in the deep waters of the Pearl River Mouth Basin. The results show that the large-scale low-angle detachment fault activity generated by the brittle-ductile deformation process in the crust is the main mechanism for extension, thinning and rupture of the crustal margin lithosphere during rifting period. The balanced lifting of the crust during rifting period, the rotation of hanging wall blocks on the fault zone and the development of the large low-angle major fracture transition zone led to the deep-water fault zone of Eocene Wenchang Formation-Enping Formation with wide deep faulted depression structure, and the large delta-lake sedimentary response system during sedimentary period. The slow sedimentation during pyrolysis period and the abundant unilateral source supply resulted in the development of the continental shelf slope-break zone during the sedimentary period of Oligocene Zhuhai Formation, thus forming the regressive prograding sequence combination. The large-scale marine shelf margin delta and the continental slope deepwater canyon/deep water fan system were developed in Baiyun depression and its southern sags separately. During the post-crack thermal subsidence period, stepped settlement and sufficient north unilateral provenance system controlled the migration of the shelf slope breaks from south to north. Thus, the shelf slope breaks stably distributed on the north slope of Baiyun, thus forming a transgressive aggradated sequence combination. The continental shelf margin delta and deep water fan systems are vertically stacked. Under the background of the Cenozoic continental marginal crust detachment and thinning, the wide and deep faulted depression structure in the rifting period, the stepped subsidence in the late stage of rifting and the supply of unilateral provenance system resulted in the development of a large delta-lake sedimentary system in the continental margin deep water areas during rifting period, as well as a deep water gravity flow response system in the continental shelf margin delta and continental slope of large continental slope breaks during the late period of rifting. Eventually, a distribution pattern was developed as the concentrated distribution of large-scale source rocks, a longitudinal stepped reservoir-cap assemblage and two continental slope breaks controlling large-scale favorable oil and gas accumulation.