Intake and exhaust system is one of the important parts of power systems of the ships, because the resistance performance will influence the whole performance of the main propulsion engine. Therefore, the performance of the intake and exhaust systems are always studied in advance inside laboratories before they are built as the real ship system. In this paper, both CFD and experiment methods are employed to investigate the pressure loss performance of intake and exhaust systems. The RANS simulation with k-ε turbulence model is done by the commercial code ANSYS Fluent. Firstly, sixteen different intake and exhaust models were calculated with the proper boundary conditions according to the former research experience. The resistance performance of the real ship intake and exhaust models was obtained. Then a simplified geometric model was proposed to simulate the performance of the complex real ship intake and exhaust system effectively and efficiently. This kind of novel simplified model can reproduce the geometrical structures of the real ship under lab environments, which can easily adjust the angle of the resistance simulators. Additionally, a low speed wind tunnel system with a kind of small-scale aerodynamic model has been made and its pressure loss performance was measured under laboratory conditions in the experiment. Finally, the simulation results are compared with the experimental data. The results show that the simulation method employed in this paper is suitable to do such research work with high accuracy. And the simplified model can be used to mimic the resistance performance of the real ship intake and exhaust systems.