Disclosed is a mask for the thin film packaging of a flexible OLED panel, the mask comprising a mask frame (20) and a mask body (10) arranged inside the mask frame (20). A shielding area (11) and an opening area (12) are defined in the mask body (10), wherein the opening area (12) corresponds to an AA area of the flexible OLED panel. A precise mask area (14) is further defined in the opening area (12), and corresponds to a bending area of the flexible OLED panel. Mutually separated precise openings (140) are defined in the precise mask area (14), and the size of each of the precise openings (140) corresponds to one or more pixel points. The mask for the thin film packaging of the flexible OLED panel can be used to manufacture a modular packaging layer (132), so that the inner stress of an inorganic thin film at a position during bending is reduced, and therefore, the risk of damaging the packaging layer during repeated bending of the bending area is reduced.