Abstract: As a kind of continuous compressible fluid, the atmosphere shows stratified fluid characteristics. Changes in its state can be described with the partial differential equations composed of Newton's second law, the first law of thermodynamics, continuity equation and the state equation of ideal gas. In order to better describe dynamical processes in the atmosphere, three-dimensional (3D) Coriolis force is considered in the nonhydrostatic dynamic core of GRAPES model. Rearrangement of the coefficients for the Helmholtz equation induced from the semi-implicit semi-Lagrangian integration of the atmospheric dynamics makes the corresponding solving procedure the same as in the original model, and the dynamical process is successfully updated. A series of idealized 3D hydrostatic experiments were carried out to test the effect of the stability of the GRAPES dynamical core. Numerical results reveal that the integration of the model dynamic core with 3D Coriolis force is stable, and the full consideration of the Coriolis force improves the computational accuracy of the 3D scalar and vector prognostic quantities. In a 15-day integration of the model with a configuration of 1°×1° horizontal resolution, the l₁ and l₂ norms of the scalar Π' are 0.00023 and 0.0004, respectively, and those of the 3D wind vector are 0.002 and 0.003, respectively, one order less than the corresponding norms of the original model. The new frame also shows an excellent numerical stability and computational effect in the idealized Rossby-Haurwitz wave propagation, mountain-Rossby wave and baroclinic wave experiments.