Abstract: The grouting and lining zones, as low permeability media, deviate from Darcy’s law to non-Darcy’s law under low hydraulic gradients. Based on the mirror image method and the theory of seepage mechanics, this paper assumes that the grouting and lining zones follow the Hansbo non-Darcy seepage model. Analytical solutions for the seepage field in subsea twin-parallel asymmetric tunnels are derived, considering both linear and nonlinear seepage simultaneously. The proposed method is validated through degeneration verification, comparative analysis with engineering cases, and comparison with numerical simulations. In addition, an analysis is conducted on the effects of parameters such as tunnel spacing, relative size, nonlinear parameters (m) of grouting and lining zones, critical hydraulic gradient (i_l), and thickness ratio (t₁) on the water inflow and pore pressure of tunnels. Results indicate that the decreases of tunnel spacing and relative size (R) both lead to a decrease in water inflow. The increase of the nonlinear parameters of grouting zone makes the grouting zone denser, reducing water inflow and providing better protection for the lining. Similarly, increasing the ratio of grouting zone to lining zone thickness (t₁) can also reduce water inflow, enabling the grouting zone to withstand greater pore pressure.