Offshore wind power has been the fastest growing form of renewable energy for the last few years. It is reasonable and efficient utilization of offshore wind power resources that is one of the effective means to achieve carbon neutrality. With the offshore wind farms gradually developing into deep and far sea, attentions are paid to the bearing characteristics of foundations for offshore wind turbines more and more. Therefore, it becomes significantly important to explore new foundations, which can effectively promote the development of offshore wind power. In order to provide assistance for offshore wind farms construction, numbers of researcher have made a lot of contributions to study new foundations for offshore wind turbines. A series of numerical calculation models for pile-bucket composite foundations in heterogeneous saturated clay are established by the finite element software ABAQUS in this paper. It is compared that the bearing characteristics of pile-bucket foundations in different heterogeneous saturated clays under vertical loading V, horizontal loading H, and bending moment M. And the priority of influencing factors is studied through the orthogonal test. The results show that saturated clay coefficient K has little effect on vertical bearing capacity coefficient NcV. Saturated clay coefficient K is different, but the size of the vertical bearing capacity coefficient NcV is almost unchanged for a certain foundation. There is a great interaction between the diameter D and the buried depth L of the bucket structure, when it comes to the impact of bucket shapes on bearing capacity coefficient in the three directions. It is easily perceived that the diameter D of the bucket has a greatest influence on the bearing characteristics of the pile-bucket composite foundations. Therefore, the bearing characteristics of the composite foundations can be effectively improved by increasing the diameter D of the bucket. The research results provide a reference for the design of the pile-bucket composite of offshore wind turbine.