A foldable display device is provided and includes: a first housing, a second housing rotatably connected to the first housing, a flexible display module, and a rigid foldable functional layer. A side of the flexible display module is disposed on the first housing and the second housing, and the rigid foldable functional layer is disposed on another side of the flexible display module. Furthermore, the rigid foldable functional layer is disposed on a light-emitting side of the flexible display module.