Bucket foundation is a lightweight foundation structure suitable for silty soils of low bearing capacity. Its stability calculation relies on the interaction of the bucket body and the earth to resist external loads，so earth pressure is a key factor for stability calculation and its distribution law and size play a role in control of the calculation results. Model test results verify the rationality of the finite element model parameter values, so active and passive earth pressure distribution law of wave loads and backfill loads under different soil layer are studied by the method of finite element numerical simulation. These results are obtained that the size of earth pressure is affected on the displacement form；the earth pressure distribution change is caused by the interaction between the different soil layers；the correction factor of the theoretical formulae as well as the construction sequence is affected on earth pressure distribution shape. The result of this paper identified the different loads and soil distribution to earth pressure effect law，amendments to the traditional formula of active and passive earth pressure，and laid a foundation for stability calculation of bucket-based structure.