This paper analyzes the influence of excavation and dock wall on the bearing capacity of the dock slab by software PLAXIS. The results indicate that the current design method is conservative. The pile-soil interaction is taken into account to obtain the vertical load-settlement relationship of the dock slab and the load shared by the pile and soil. The theoretical model agrees with the fact quite well. The comparison of results of the finite element has been carried out with calculated results, which proves its feasibility for the analysis of piled raft foundation of dock slab.