Abstract: The high-resolution profile survey of shallow strata, high-resolution multi-channel seismic survey of small track distance, side scan sonar, surface geological sampling, drilling and other survey mean resulted in revealing of the basic geological features, including seabed topography and landform, type and distribution of the seabed, stratigraphic structure, active faults, seismicity and stress in the trans-sea passage area of the Bohai Strait, summary of the geological hazards, the Quaternary stratigraphic framework and the evolution of palaeo-environment, and description of the main achievements of crustal stability evaluation in this area.The Bohai Strait is characterized by well-developed active faults, active neotectonic movement and unstable crust.The crust stability in the eastern part of the northern Yellow Sea Basin is relatively good, while that in the western part of the Bohai Basin and the southern part of the strait area is relatively poor.The latest survey results in the Bohai Strait can provide basic data and decision-making basis for the construction of cross-sea passage projects, serve for disaster prevention and mitigation of major national sea-related engineering, and promote the understanding of the evolution of paleoclimate and environment in the Bohai Sea area.