In this paper, the forced vibration test is taken in the Dragon Washbasin. When a certain frequency excitation force is excited on the shell of the Dragon Washbasin, different shapes gravity waves will appear. Because of the object is a water waves, the magnitude is large and water splashes, it asks more of the measurement. According to the crossed optical axis theory we designed the experiment system. The space between the raster is adjustable, and we use high speed camera taking pictures. By using median filter, Fourier transformation, frequency filter, Inverse Fourier transform etc, the 3D height information of the first-order and second-order gravity waves of any time is got. Through the processing of a series of pictures in one period we got the time histories of any point of the waves. The work of this paper is a new trial of the measurements of the free surface wave in the fluid-shell coupled system, and the experimental data are significant references for the further theoretical study.