Abstract: Within 40-meter water depths, large-diameter monopiles have become the preferred foundation type for offshore wind turbines due to their high efficiency and low cost. Our research team has previously established a "p-y+M-θ" model for large-diameter monopiles under cyclic horizontal loading in clay, which has been successfully applied in numerous engineering analyses. However, the analytical model for horizontally loaded monopiles in sand remains under investigation, with no unified standards yet established. This study develops a "p-y+M-θ" model for predicting the response of horizontally loaded piles in sand under static loading, which is then extended to cyclic loading to analyze displacement ratcheting and shakedown deformation behavior. Compared with the centrifuge and field test results, its is found that the model can effectively predict the displacement response characteristics of monopile under different cyclic loads. The "p-y+M-θ" model proposed in this paper offers advantages such as few parameters and high precision, making it a valuable tool for the design and analysis of monopile foundations in sand for offshore wind turbines.