To provide reference for selecting basic parameters for hydrodynamic performance analysis of monohull based on CFD, relevant convergence analysis were carried out. The influence of grid dimension, turbulence model and time step on convergence of ship hydrodynamics calculation is analyzed. Some optimized parameters and models are provided for ship hydrodynamics calculation using CFD, and the proposed model has been validated by tank model experiment. The following recommendations are provided from this study for ship seakeeping CFD simulation: using unstructured mesh with dimension of 2.83% ship length for domain grid generation, using Realizable k-ε turbulence model and setting 1/200 wave encounter period as calculation time step. This paper provides some suggestions in selecting the parameters for the calculation of ship resistance and seakeeping based on CFD.