Each flight experiment needs a lot of labor power and costs much money. Therefore several simulation experiments must be conducted on the ground beforehand. The simulation experiment of a flight above the sea is more complicated than the simulation experiment of TAN (Terrain aided Navigation), since even for a fixed sea region, height data of sea wave are time-variant, so it is impossible to perform a simulation experiment directly using the historical flight data obtained in the sea region before. Instead, all the data must be generated by simulation, including the data of sea wave field, the data of air movements, and the instructions of the controlling system and the flight path of the flying machine. Because the radar height meter is one of the inputs of the controlling system, it is necessary to simulate the radar height meter. We give an effective method of simulating radar height meter provided that the simulation data of sea wave field are known. Compared with other methods, our method is simple and easily performed because the amount of data used is small and the arithmetic is convenient.