Concrete expansion pile represents a new type of high-efficiency and energy-saving variable-section filling pile and it is formed by special construction technology and equipment, this technology has been basically mature which has been gradually applied to engineering in recent years. It has high bearing capacity, small settlement and uniformity, good economic and social effect, strong anti-overturning ability and flexible design[1]. In this paper, with expansion disk spacing under bearing force as the main parameter variable, numerical simulation is carried out by ANSYS finite element software to analyze the variation relationship between horizontal displacement of the pile top, bending moment of the pile and soil stress around the pile of different disk spacing models under horizontal load, and determine the influence of disk spacing parameter on horizontal bearing capacity of the concrete expansion pile. Through the research of this paper, the influence of failure mode of concrete expansion pile and size of the disk spacing on the horizontal bearing capacity under the horizontal load is qualitatively determined, which provides a theoretical basis for improving design theory and practical application of concrete expansion pile.