In the process of production, the addition of benzethonium chloride to the wipes is achieved by impregnation of the pharmaceutical solution, that is, the adsorption of benzethonium chloride molecules in the pharmaceutical solution by nonwovens. Because the process of benzethonium chloride adsorption is a very short time, the study about the adsorption rate of benzethonium chloride by nonwovens has not been reported. In our work, the adsorption of benzethonium chloride by nonwoven was as research subject, and according to the fact that the characteristic absorption peak of benzethonium chloride was at 269 nm, by building an on-line kinetic ultraviolet-visible spectroscopy monitoring system and using a peristaltic pump to transport the solution to the flow cuvette of the spectrophotometer for cyclic detection, the absorbance value of benzethonium chloride solution in the adsorption process can be determined online. Based on the relationship between the absorbance value and benzethonium chloride, the adsorption of benzethonium chloride was deduced and calculated. Therefore, a method for the accurate and rapid determination of benzethonium chloride adsorption by nonwoven was established, which is suitable for on-line monitoring of the concentration of benzathonium chloride solution. The adsorption process of benzethonium chloride was theoretically analyzed by Weber and Morris diffusion model, which provides guidance for further study on the adsorption of benzethonium chloride by nonwovens. The results showed that the adsorption of benzethonium chloride is a continuous dispersion process; The first stage of linear adsorption is related to the surface diffusion, the second stage is the intergranular diffusion process and the third stage is the equilibrium dynamic process of adsorption and desorption. The diffusivity constant of the first stage (41.60) is much higher than that of the second stage (15.63), indicating that surface diffusion plays an important role in the whole adsorption process. This paper can provide good guidance for rational selection of benzethonium chloride concentration and optimization of process in production of wet wipes.