An OLED encapsulation package, a display device and a packaging method are disclosed. The OLED encapsulation package includes a substrate, a cover board and a encapsulation unit located between the substrate and the cover board; the substrate is provided with display components thereon, and the encapsulation unit encapsulates the periphery of the display components; the encapsulation unit includes at least a moisture sensitive layer therein, and the moisture sensitive layer is capable of discoloring upon encountering with water.