Abstract: To reveal the horizontal bearing characteristics of composite bucket foundation in silty sand, the finite element software is used in this paper, and the numerical model is verified by the results of centrifugal model test. Main conclusions are as follows: on the front side, the distribution of earth pressure is arched and earth pressure at the bottom is reduced; on the rear side, the earth pressure distribution is roughly triangular, and the earth pressure on the bucket wall in vertical load direction is close to the static earth pressure. There is a linear relationship between the bucket wall earth pressure and cosθ (the angle between the calculation point and the load direction). With the increment of load level, the rotation center of composite bucket foundation moves up and to the load direction, and as the load reaches bearing capacity, the rotation center is located at bucket tip. The aspect ratio of composite bucket foundation does not affect the motion law of the rotation center, and the effect of rotation center on the vertical position of rotation center is obviously greater than that on the horizontal position. The research results provide a reference for optimal structural design of the foundation.