Abstract: The analytical calculations of unsaturated steady-state seepage in the widespread layered soils are relatively rare. Based on the Darcy seepage theorem and the continuity condition of soil layer interface, a mathematical model describing the steady seepage process of unsaturated layered soil is constructed. The analytical expressions of matric suction, effective saturation and suction stress along the elevation for the same profile of layered soil are obtained by using the separation variable technique and mathematical induction. The analytical algorithm is validated based on the COMSOL numerical analysis platform, which enables the analytical solution of the steady-state seepage process in unsaturated layered soils. Then, the influence of soil layer interface on seepage process is discussed and the sensitivity analysis of parameters is carried out. The analysis shows that: (1) under the same infiltration conditions, the matric suction of sand at the same elevation is the highest, while that of clay is the lowest; The difference in surface seepage rate has the greatest impact on the distribution of effective saturation in the silt layer, while the sand layer has the smallest impact. (2) The suction stress in the clay layer increases almost linearly, while the suction stress in sand increases first and then decreases along the elevation; The presence of soil interface can affect the growth rate of matric suction along the elevation, leading to a sudden change in the distribution of effective saturation and suction stress along the elevation. (3) Gardner model parameters α The smaller the value, the greater the matric suction value at the same elevation, while the smaller the k_s value of saturated soil, the slower the growth rate of matric suction; α The smaller the value of k_s, the slower the rate of effective saturation reduction; α The smaller the value or the larger the value of k_s, the greater the suction stress value at the surface. The research results can provide certain theoretical support for engineering geological problems such as slope stability.