Using historical investigation data to analyze the overall stability of the existing sea embankment,the calculated value of safety factor is often low,which is not consistent with the stability status quo.The situation seriously affects the design of the seawall reinforcement.Based on an old sea embankment stability analysis and new sea embankment design case,this paper densely distributes the spacing of investigation points of typical sections.Combined with estimation of the consolidation degree and undrained shear strength increment of the ground,this paper analyzes the shear strength of foundation beneath the embankment emphatically.On the basis of determining the stability of the status quo of seawalls,the seawall reinforcement scheme is greatly optimized,which can provide reference for the investigation and design of similar projects.