A display device packaging method comprises steps of: providing a first substrate including a display region and a non-display region that surrounds the display region; providing an adhesive material which is disposed on the first substrate and formed into a closed curve surrounding the display region, wherein the closed curve has a start zone and an end zone connected to the start zone; providing a light-blocking element at least covering the end zone; providing a heating source radiating to the light-blocking element and moving the heating source to the start zone of the adhesive material; and scanning the adhesive material from the start zone to the end zone along the closed curve by the heating source. A display device is also disclosed.