Abstract: An experiment on surface-wave evolution characteristics of thin film falling down a vertical plate was completed by means of large-scale water film stabilities experiment rig. Surface wave speed, wave-length, and frequency were measured and analyzed with capacitance measuring instrument of thin-film thickness and high-speed video camera. The experimental result indicates that surface wave speed, wave-length, and frequency are weakly proportional to water film Reynolds number, respectively. At the same time, the feature of interfusion between ripples is summarized based on careful observation for process of interfusion between ripples.