The seepage field in a layered soil excavation is significantly different from that in a homogeneous soil layer,and the most likely location for a sudden surge accident is also different.Therefore,accurately determining the two-dimensional steady-state seepage field in a layered soil excavation is an important issue in basic engineering construction.For the steady-state seepage problem in a layered soil excavation,the soil around the excavation was divided into multiple regions according to the layered conditions.The series solution of the water head distribution in each region was given by using the superposition principle and the separation of variables method.The explicit analytical solution of the water head distribution of the two-dimensional steady-state seepage field in the layered soil excavation was obtained according to the continuity conditions between the regions and the orthogonality of the Fourier series.The water head distribution and retaining wall water pressure calculated by the analytical solution were verified with the results of finite element software,and the analytical solution was degenerated into a single-layer soil form and compared with the semi-analytical solution.The results are in good agreement,verifying the correctness and effectiveness of the analytical solution.The analytical solution is compared with the water pressure calculation method considering the interaction between water and soil and the equivalent permeability coefficient method.Based on the analytical solution,the calculation formulas for the escape ratio drop,retaining wall water pressure and anti-surge safety factor in the excavation are further given.The anti-surge performance of the excavation in layered soil is analyzed and compared using the analytical method and the equivalent permeability coefficient method in combination with engineering cases.The research results show that the analytical solution is more in line with the actual situation when solving the seepage field in a layered soil excavation;when considering the difference in permeability coefficients between different soil layers,the water head changes faster in the soil layer with poor permeability;when the permeability coefficient of the upper soil body is small,the risk of sudden surge at the soil layer interface is greater than at the bottom of the retaining wall;the equivalent permeability coefficient method has a large error when solving some seepage fields in layered soil excavations.