The rocker flap wavemaker method is taken as an example to derive the wavemaker equation and the waveabsorber equation. Then, the wave parameters are linked to the movement characteristics of wavemaker plate. The verticalplate wavemaker model and rockerflap wavemaker model are designed to achieve the numerical simulation with the Fluent software. In the simulation, the UDF is used to control the movement of wavemaker plate and additional momentum source is used near the wall to absorb wave. The advantages and disadvantages of the two methods are anaylzied. The verticalplate wavemaker method is suitable for small wave and has no special requirement for power source, while the rockerflap wavemaker method is suitable for medium wave and the generated wave is better. According to the simulated data, the physical prototype is designed and manufactured, the wave height is measured in the experiments. The waver generator design method based on the numerical simulation can identify the wavemaker type and key parameters quickly to shorten the design cycle and reduce the development costs, which has important reference significance in developing novel wave generator.