To investigate the deformation and embedment depth of cantilever steel sheet pile walls considering the passive resistance at the pile base, a comprehensive review of relevant literature was conducted, coupled with extensive calculations for cantilever pile excavation support systems. It was observed that a reverse bending point exists at the base of the cantilever steel sheet piles. The position of the inflection point was solved according to the bending moment equilibrium equation of the soil pressure on the pile. The retaining structure was subsequently divided into three sections based on the excavation bottom and the reverse bending point, and deformation and force analyses were performed for each section. Differential equations governing the deflection and bending of each pile segment were established. By applying boundary and continuity conditions, the deflection equations for each pile segment were solved, leading to the determination of the embedment depth for cantilever steel sheet piles. The research resultes indicate that the locations of reverse bending points exhibit certain regularities across different soil layers and excavation depths. The proposed modification method not only accounts for the passive soil resistance below the reverse bending point but also aligns more closely with the actual force conditions experienced by cantilever steel sheet piles, resulting in safer and the calculation results are safer.