Organic light emitting diode (OLED) device will have a bright future in the display field, because of its advantages. The most important advantage is the ability to achieve flexible display and be made into flexible organic light emitting diode (FOLED). OLED materials are extremely sensitive to vapor and oxygen. The vapor and oxygen penetrating into the interior of the device are the main factor that affects the lifetime of OLED. Thus, encapsulation technology is important to OLED device. The substrate material and encapsulation technology used in FOLED are reviewed and meanwhile, their advantages and disadvantages are fully discussed, and the progress of the recent research on novel substrate material and encapsulation method are described.