An LED display device includes an installing pillar, a first fixing plate, an enclosure module, an LED display screen module and a first connection member, the enclosure module includes a front surface for display and a rear surface opposite to the front surface, the installing pillar is positioned on the rear surface of the enclosure module, the first fixing plate closely contacts the installing pillar, the first fixing plate defines a first fixing hole, the first connection member extends through the first fixing hole from the rear surface of the enclosure module and connects with the enclosure module, thereby clamping and securing the installing pillar between the first fixing plate and the enclosure module, and the enclosure module is fixed to the installing pillar via the first fixing plate and the first connection member, the LED display screen module is assembled to the front surface of the enclosure module. Thereby the LED display device can be maintained with a high flexibility and it is convenience for operation, and the cost thereof is low, thus a front/rear side-maintenance type assembly can be realized.