The work aims to study the drag-reducing property of super-hydrophobic material to propose an accurate and reliable numerical simulation method. A 3-D model of ship made of super-hydrophobic material was built for the numerical simulation of viscous flow around the ship in considering free surface. Because the contact angle was an important parameter to evaluate super-hydrophobic property of the material, the change in corresponding resistance values was studied by changing the surface contact angle. The accuracy of study on drag-reducing property of super-hydrophobic material was verified with such model and method by integrating theoretical calculation, numerical simulation and experimental study. With the increase in surface contact angle, the resistance applied on the ship was reduced. The resistance of ship made of super-hydrophobic material was reduced by 41% compared to that made of hydrophilic material and by 24% as to the ship made of general hydrophobic material. The amount of resistance of ship model obtained in the simulation was basically consistent with theoretical calculation and experiment results and the errors were respectively within 4.6% and 8%. Through the study on the drag-reducing property of super-hydrophobic material based on the ship model, an effective research method is proposed based on numerical simulation to provide certain guidance for researches on other properties of super-hydrophobic material.