Abstract: Solitary wave characteristics of liquid film are important factors affecting the surface morphology and heat transfer itself. An experimental platform for falling liquid film flow was built to measure the film flow on an inclined triangular plate, and to further analyze the variation law of velocity and frequency of solitary waves at different inclination angles, Reynolds numbers and distance along the path. Results show that the velocity of solitary waves is positively correlated with Reynolds number, and that on a triangular wall is higher than on a flat plate, which increases gradually along the flow direction. The frequency characteristics of solitary waves have no obvious correlation with Reynolds number, inclination angle and distance along the path, but are closely related to their own generation processes.