Abstract: Based on measured geophysical data and geological sample data, a geological hazard risk assessment system was established with evaluation indicators including earthquakes, direct geological hazards, indirect geological hazards, and critical erosion shear stress of sediment substrates using analytic hierarchy process and fuzzy mathematics evaluation method. The geological hazards in the study area were classified into five risk levels: low risk, relatively low risk, medium risk, relatively high risk, and high risk. The study area was divided into 1 008 units in grid of 2 km × 2 km, and each unit was evaluated one by one. Results show that more than 75% of the sea area south of Caofeidian is at low and medium-low risk, and 25% is at relatively high and high risk. High-risk areas are mainly distributed in the northeast of the study area, mainly controlled by active faults. The evaluation results are consistent with the identified distribution characteristics of geological hazards, and can provide a scientific basis for engineering construction planning, construction safety assurance, and disaster prevention in this sea area.