Based on Shanghai Yangtze River tunnel, the settlement rules of dike top plane were studied when tunnel penetrate dike with numerical simulation method. It is found that the radius and convergence rate of tunnel have relative simple influence on settlement of dike top plane, while elastic modulus of dike, thickness of soil clay uplapping tunnel and distance between two tunnels have relative complicated influence on settlement of dike top plane; the settlement of dike top plane increase when the radius and convergence rate of tunnel increase; the maximal settlement and maximal difference settlement of dike top plane right above tunnel decrease when the elastic modulus of dike increase, and tend to a steady value; the maximal settlement and maximal difference settlement of dike top plane right above tunnel decrease when the thickness of soil clay uplapping tunnel increase, and then decrease slowly when the thickness of soil clay uplapping tunnel is over 20 m; the settlement of dike top plane increase with the increment of distance between two tunnels when the distance is less than 10 m, and it is inverse when the distance is over 10 m; the maximal settlement and maximal difference settlement of dike top plane have S shape relation with the distance between two tunnels. The following conclusions can be drawn that the measures such as enlarging the elastic modulus of dike, reducing the convergence rate of tunnel, taking appropriate radius, thickness of soil clay uplapping tunnel and distance between two tunnels, in order to reduce the settlement rules of dike top plane when tunnel penetrate dike.