The adhering device of the present application includes a chamber; a carrying platform having a groove formed thereon; a pressing block assembly for supporting the flexible display panel, and fitting the flexible display panel toward the curved cover plate at a preset rising speed; a clamp assembly for holding the flexible display panel, and when the flexible display panel is adhered to the curved cover plate at a preset ascending speed, the clamp assembly starts to rotate until the flexible display panel and the curved cover plate completely adhere together with the display panel separation.