An organic electroluminescent device and a manufacturing method thereof, and a display device. The organic electroluminescent device comprises comprising a base substrate, a packaging structure, an organic electroluminescent structure located between the base substrate and the packaging structure, and a flexible printed circuit board; the base substrate being provided with a peripheral wiring structure electrically connected with an internal wiring of the organic electroluminescent structure; the peripheral wiring structure including a welding part. The welding part has a first surface facing the base substrate, at least a portion of the first surface being exposed to electrically connect with a welding terminal of the flexible printed circuit board.