The reinforcing scheme of the seawall is studied because of the complex and changeable geological conditions of the foundation in the north levee of Da-xiao-yushan. 1）The characteristics of seawall foundation with deep soft soil and deep groove are analyzed，and the geological characteristics are summarized. 2）The stability of typical sections with different geological characteristics，especially deep groove sections are analyzed by the arc sliding method. 3）The optimization suggestions for structural schemes are proposed. The research results show that it is reasonable to use the blasting compaction foundation reinforcement scheme，and the range and elevation of the rock platforms have an important influence on structural optimization. The optimization scheme can effectively reduce the amount of rock and the cost.