An LED display device, comprising: a rectangle framework, comprising a frame, a first transverse beam and a second transverse beam arranged inside the frame at intervals, and a strip-like gap being formed by the first transverse beam, the second transverse beam and a part of the frame; an adapter plate assembly, comprising a fixed plate mounted at the strip-like gap and an adapter plate detachably arranged on a rear side of the fixed plate, and the fixed plate being provided with a lock; and a display module, and a rear side of the display module being provided with a first strip-shaped lock hole, wherein, the lock comprises a rotary shaft rotatably arranged on the fixed plate and a first lock tongue arranged on the rotary shaft, the first lock tongue is able to go through the first strip-shaped lock hole and has a first unlocking position corresponding to the first strip-shaped lock hole and a first locking position that is staggered with the first strip-shaped lock hole, and the adapter plate fits the display module through a connector in a plugging-in manner; characterized in that, the display module is mounted on a front side of the rectangle framework through a magnetic attraction structure and the adapter plate is provided with a second strip-shaped lock hole, and the lock further comprises a second lock tongue arranged on the rotary shaft; the second lock tongue is able to go through the second strip-shaped lock hole and has a second unlocking position corresponding to the second strip-shaped lock hole and a second locking position that is staggered with the second strip-shaped lock hole, wherein, the second lock tongue is located at the second unlocking position when the first lock tongue is located at the first locking position, and the second lock tongue is located at the second locking position when the first lock tongue is located at the first unlocking position. a rectangle framework, comprising a frame, a first transverse beam and a second transverse beam arranged inside the frame at intervals, and a strip-like gap being formed by the first transverse beam, the second transverse beam and a part of the frame; an adapter plate assembly, comprising a fixed plate mounted at the strip-like gap and an adapter plate detachably arranged on a rear side of the fixed plate, and the fixed plate being provided with a lock; and a display module, and a rear side of the display module being provided with a first strip-shaped lock hole, wherein, the lock comprises a rotary shaft rotatably arranged on the fixed plate and a first lock tongue arranged on the rotary shaft, the first lock tongue is able to go through the first strip-shaped lock hole and has a first unlocking position corresponding to the first strip-shaped lock hole and a first locking position that is staggered with the first strip-shaped lock hole, and the adapter plate fits the display module through a connector in a plugging-in manner; characterized in that, the display module is mounted on a front side of the rectangle framework through a magnetic attraction structure and the adapter plate is provided with a second strip-shaped lock hole, and the lock further comprises a second lock tongue arranged on the rotary shaft; the second lock tongue is able to go through the second strip-shaped lock hole and has a second unlocking position corresponding to the second strip-shaped lock hole and a second locking position that is staggered with the second strip-shaped lock hole, wherein, the second lock tongue is located at the second unlocking position when the first lock tongue is located at the first locking position, and the second lock tongue is located at the second locking position when the first lock tongue is located at the first unlocking position.