To discuss the influence of ship waves on the cross-section size of a navigation tunnel, a numerical model of ship wave propagation in navigation tunnel was established based on the open source package FUNWAVE-TVD of completely nonlinear Boussinesq equation. The spatial and temporal distribution of maximum ship wave height and lateral velocity in navigation tunnel was emphatically analyzed, and the influences of ship draft, Froude number, water depth and width of navigation tunnel and ship type on the maximum ship wave height and lateral velocity in navigation tunnel were discussed. Based on the duration analysis of ship wave height, an empirical formula for calculating the vertical section size of navigable tunnel was proposed. Combined with the transverse velocity generated by ship wave breaking and the current inland navigation standards, the reference of water flow conditions for safe navigation in navigable tunnel and the construction requirements of tunnel transverse section size were given. The results show that, due to the reflection of the vertical walls on both sides of the tunnel, the coda wave is easily affected by the navigation tunnel bank wall to form a large wave height, and the closer it is to the bank wall of the tunnel, the lower the maximum transverse velocity is. When the ship reaches the design draft, the ship wave is not easy to break, and the maximum transverse velocity is low. Keywords: ship wave; navigation tunnel; cross-section size; Boussinesq equation; FUNWAVE-TVD 〖FL