The invention relates to a processing method of a window-sealing transparent thin film of a window type packaging box. The method specifically comprises the steps that a plurality of folded lines are arranged on the window-sealing transparent thin film, and the window-sealing transparent thin film is directly subjected to half-cutting treatment along the folded lines; or the window-sealing transparent thin film is subjected to indentation treatment along the folded lines to obtain indentations firstly, and then the window-sealing transparent thin film is directly subjected to half-cutting treatment along the indentations, wherein half-cutting treatment means that the window-sealing transparent thin film is downwards cut by a certain depth but not completely cut along the plane, perpendicular to the thin film, of the folded lines or the indentations. The processing method has the beneficial effects that through half-cutting treatment on the folded lines or the indentations, the problems that in a traditional processing method of the window-sealing transparent thin film, the indentation folded lines are not prone to being reduced, and tension is large after reducing are solved, and production efficiency of the processing method is high; and additionally, after the indentation folded lines are changed to be half-cutting folded lines, the tonnage requirement for an indentation device is greatly lowered, the lower the tonnage is, the smaller the energy consumption becomes, and the production cost can be reduced.