The current problems are hot spots in recent years. With the rapid development of modern computer technology, numerical simulation technology has become an important means of scientific research, and the correlation numerical solution of two-dimensional shallow water equation is endless. In this paper, the two-dimensional shallow water equation was discretized by the finite element weighted lumped mass method, and the time is discretized by the forward Euler scheme, then the planar two-dimensional hydrodynamic model was established. The water boundary condition was defined by harmonic analysis method. The two-dimensional hydrodynamic model was applied to Daya Bay area and verified according to the measured meteorological data. Therefore, the hydrodynamic model established in this paper can be used to study the actual water flow in Daya Bay area.