This article proposes a method for calculating the line width of aerosol printing based on image processing and analyzes the line width results obtained using this method, aiming to establish an accurate mathematical model between parameters and line width. This article conducts experiments using carrier gas and sheath gas as parameters in aerosol printing and uses an industrial camera to characterize the printed lines. The line images are processed in MATLAB to obtain high-precision printed line widths. Analyzing the line width data after image processing, it was found that the line width increased with the increase of carrier gas and decreased with the increase of sheath gas. Then, using the discovered regularity, mathematical relationships between sheath gas and line width, and carrier gas and line width are established. The calculation method of print line width used in this article is highly accurate and efficient and establishes a functional relationship analysis model that can accurately describe the relationship between variables and line width, guiding printing-specific line widths.