Abstract: The bucket foundation breakwater is a new type of port and coastal engineering structure suitable for soft foundations and deep water waves, the stability of which is sustained by the bucket foundation penetrated in soils. According to the motion mode of the bucket foundation breakwater in the limit state, a limit equilibrium method is established in consideration of its three-dimensional geometry, force characteristics and rotation point position. Compared with the finite element method, the limit equilibrium method is consistent in the calculated results. But the limit equilibrium method has faster calculation speed and higher efficiency. So it is more convenient in engineering application. According to the project of extending breakwaters in Tianjin Port, the stability of the bucket foundation breakwater is analyzed. The results show that when the height of the bucket is 8 to 10 m, the anti-sliding, anti-overturning and vertical bearing capacities of the bucket foundation breakwater in the project all have high degree of safety.