A foldable display apparatus, comprising: a flexible display panel, comprising a first screen area and a second screen area that are capable of being folded relative to each other; a multi-layer protective structure, configured to carry the display panel, wherein the multi-layer protective structure comprises a first protective layer located on a side of the multi-layer protective structure that is away from the display panel; and a mainboard connection structure, disposed inside the multi-layer protective structure and configured to enable electrical connection and signal transmission between two mainboards (131, 132) located on two foldable bodies of a terminal device, wherein the mainboard connection structure comprises: a wiring layer, an insulation layer, and a shielding layer that are stacked at the first protective layer in sequence, wherein the shielding layer is closer to the display panel than the wiring layer, and the shielding layer entirely covers the wiring layer; the wiring layer comprises a metal wire; a position of a first end of the metal wire corresponds to the first screen area, and is formed with a first bonding pad; a position of a second end of the metal wire corresponds to the second screen area, and is formed with a second bonding pad; and a first pad area in which the first bonding pad of the metal wire is exposed and a second pad area in which the second bonding pad of the metal wire is exposed are formed at the first protective layer; a first connecting piece, wherein a first end of the first connecting piece is disposed in the first pad area and is electrically connected to the first bonding pad of the metal wire; and a second connecting piece, wherein a first end of the second connecting piece is disposed in the second pad area and is electrically connected to the second bonding pad of the metal wire. a flexible display panel, comprising a first screen area and a second screen area that are capable of being folded relative to each other; a multi-layer protective structure, configured to carry the display panel, wherein the multi-layer protective structure comprises a first protective layer located on a side of the multi-layer protective structure that is away from the display panel; and a mainboard connection structure, disposed inside the multi-layer protective structure and configured to enable electrical connection and signal transmission between two mainboards (131, 132) located on two foldable bodies of a terminal device, wherein the mainboard connection structure comprises: a wiring layer, an insulation layer, and a shielding layer that are stacked at the first protective layer in sequence, wherein the shielding layer is closer to the display panel than the wiring layer, and the shielding layer entirely covers the wiring layer; the wiring layer comprises a metal wire; a position of a first end of the metal wire corresponds to the first screen area, and is formed with a first bonding pad; a position of a second end of the metal wire corresponds to the second screen area, and is formed with a second bonding pad; and a first pad area in which the first bonding pad of the metal wire is exposed and a second pad area in which the second bonding pad of the metal wire is exposed are formed at the first protective layer; a first connecting piece, wherein a first end of the first connecting piece is disposed in the first pad area and is electrically connected to the first bonding pad of the metal wire; and a second connecting piece, wherein a first end of the second connecting piece is disposed in the second pad area and is electrically connected to the second bonding pad of the metal wire. a wiring layer, an insulation layer, and a shielding layer that are stacked at the first protective layer in sequence, wherein the shielding layer is closer to the display panel than the wiring layer, and the shielding layer entirely covers the wiring layer; the wiring layer comprises a metal wire; a position of a first end of the metal wire corresponds to the first screen area, and is formed with a first bonding pad; a position of a second end of the metal wire corresponds to the second screen area, and is formed with a second bonding pad; and a first pad area in which the first bonding pad of the metal wire is exposed and a second pad area in which the second bonding pad of the metal wire is exposed are formed at the first protective layer; a first connecting piece, wherein a first end of the first connecting piece is disposed in the first pad area and is electrically connected to the first bonding pad of the metal wire; and a second connecting piece, wherein a first end of the second connecting piece is disposed in the second pad area and is electrically connected to the second bonding pad of the metal wire.