Abstract: The determination of computational models and boundary conditions is crucial for solving the non-linear seepage field of underwater tunnels.This paper systematically summarized different computational models and boundary conditions,classifying tunnel seepage boundaries into four types.We established tunnel seepage models with grouting and lining zones at both finite and semi-infinite aquifers.The analytical solutions were derived for the tunnel seepage field with different computational models and boundary conditions based on the mirror image method and Hansbo non-linear seepage theory.Comparisons with numerical solutions and previous research results validate the accuracy of our proposed method.Furthermore,the study analyzed the effects of different boundary conditions and computational models on the non-linear seepage field.It proves that multiple factors influence the water inflow and pore pressure,including the internal boundary head,water level,tunnel depth and non-linear seepage parameter.The semi-infinite aquifer model yields higher water inflow and pore pressure than the finite aquifer model.The internal and external boundary conditions also affect each other.The changes in the external boundary condition significantly impact the seepage field when the internal boundary head is larger,and vice versa.The water inflow remains unchanged when the water heads at the internal and external boundaries vary by the same magnitude.