A flexible display device and a method for manufacturing the flexible display device are provided by embodiments of the present application, which solve problems that a module of a flexible active-matrix organic light emitting diode has a poor moisture and oxygen blocking effect on a side, and an edge is prone to fracture or be peeled off when bent. A flexible display device provided by an embodiment of the application includes a display substrate, and an encapsulating film layer disposed on a surface of the display substrate. An edge of the encapsulating film layer includes a concave-convex sawtooth structure.