A drilling ship is taken as the research object, and numerical simulation and analysis are carried out on the resistance performance, free surface wave-making and ship flow field of the drilling ship by CFD method. The difference in the flow field characteristics prediction between the steady calculation method and the unsteady calculation method is analyzed in detail. In order to verify the accuracy of the calculated grid and the numerical model, the international standard module KVLCC2 is used as the object to verify the correctness of the calculation method. The method and process for the numerical prediction of the resistance and flow field of the drilling ship with large moon pool opening are developed through comparative study.