The unfrozen impinging water on the surface of aircraft will run back under the effect of the airflow. The fluctuation of water film surface will alter liquid distribution， further affecting the heat transfer characteristics during the icing accretion. The digital image projection （DIP） technology is used to provide non-intrusive and full-spatially-resolved measurements of the wavy development during the water film flow. A series of experiments are conducted in the air speeds of 16.5—45.5 m/s and the Reynolds number of water film of 24.17—96.69. The wavy characteristics of the temporally-and-spatially-resolved results are analyzed， which present the variation of the gas-liquid interface wavy parameters with both the air speed and the Reynolds number of water film， including the peak height， peak frequency， wave velocity and peak spacing. The results show that the surface wave will present varied forms in the process of water film flow. The increase of air speeds will destroy the initially periodic fluctuations and aggravate the changes of morphology. However， the increase of flow will enhance the stability of the interface and maintain the periodic fluctuation. This work is helpful to reveal the surface fluctuation characteristics of shear-driven water film， optimizing ice shape prediction and anti-icing system design.