An organic light emission display device and an encapsulation method therefor are provided. The organic light emission display device includes a base substrate, and an organic light emission diode, a barrier layer and an organic thin film encapsulation layer which are disposed on the base substrate. The organic light emission display device further includes a detection layer disposed on the base substrate; and the detection layer is configured to contact with the organic thin film encapsulation layer and make a change in the case that the organic thin film encapsulation layer overflows the barrier layer.