Abstract: The horizontal bearing behaviors of a large-diameter monopile and that with wings for offslore wind turbines are studied through the centrifuge tests and three-dimensional finite element methods. Three centrifugal model tests are conducted on the purpose of exploring the variation curves of the horizontal bearing capacity of the monopiles with different wings during the stepped horizontal loading process, and the distribution laws of their bending moment. Based on the fundamental parameters of the centrifugal model tests, three-dimensional finite element models are established to carry out the comparison with the results of the centrifuge tests. The layered foundation is adopted to factually simulate the strength features of foundation in the centrifuge field. Comparison of the calculated results with the measured results of the centrifugal model tests identifies the rationality of the established model. Furthermore, the effects of the foundation properties on the horizontal bearing capacity are studied through the numerical method. The results show that the horizontal bearing behaviors of the large-diameter monopile with wings are much more than those without wings because of the full use of the soil resistance of the shallow layer of the foundation. Increasing the length of the wing plate can effectively improve its horizontal bearing capacity.