The film-forming behavior of falling film flow with a high-viscosity fluid in clamped channels was investigated numerically and experimentally. The present work puts forward and deeply investigates a new method of falling film flow in the field of industrial engineering. The new findings from computational fluid dynamics (CFD) agree well with the experimental results. Flow patterns can be observed and divided into three flow patterns: columnar flow, partial curtain flow, and curtain flow. In terms of different flow patterns, the evolution of the liquid film along the direction of gravity was diversified, mainly including coalescence, break-up, shrinkage, and expansion. In addition, the shape of the free surface depended mainly on the physical properties of the fluid, the geometrical structure of the channel, and the spray density. The convex ratio k of the liquid film varied between 0 and 1.2, and such a wide range indicated that the free surface of the liquid film would be visually bent, resulting in a large area for the gas-liquid interface and a very high level of the film-forming efficiency. More interestingly, the desired shape of the liquid film was obtained by regulating the structural factors r and d. Based on the above conclusions, the method concerning falling film flow down clamped channels could be beneficial to enhance the heat and mass transfer in the process intensification of industrial engineering.