Disclosed are a nano-layered and transversely homogeneous PN diode, a manufacturing method therefor and an application thereof. A p-type transition metal chalcogenide film and an n-type transition metal chalcogenide film are both located on the upper surface of a dielectric layer, and are transversely connected. An electrode layer is longitudinally or transversely connected to the p-type transition metal chalcogenide film and the n-type transition metal chalcogenide film separately. The p-type transition metal chalcogenide film and the n-type transition metal chalcogenide film consist of the same transition metal chalcogenides. According to the present invention, the manufacturing method is simple, high-efficiency and low-damage p-type doping of transition metal chalcogenides can be implemented for oxygen plasma by means of magnetron sputtering, and therefore, effective and controllable doping is implemented, and the obtained diode achieves faster photoresponse and higher detection rate when used in a photoelectric detector.