The stability of OLED device is closely related to the encapsulation structure, while the quality of the encapsulation technology will have a direct impact on the lifetime of OLED device. Several familiar OLED encapsulation structures are introduced, adopting the thermal impedance model to analyse the impedance of these encapsulation structures. And by using the thermal analysis module of the ANSYS finite element analysis software, the thermal characteristics of these packaging technologies are researched, obtaining the temperature field distribution of each structures. The differences of the heat dissipation performance are derived through comparison. There′s not much difference in the effect of heat dissipation between the traditional encapsulation structure and the hybrid encapsulation structure, while the Barix encapsulation structure has the best heat dissipation performance. The simulation results show that when the thickness of the glass increases from 0.5 mm to 0.9 mm, the temperature of luminous layer of traditional encapsulation structure raises 0.124 ℃, and that of Barix encapsulation structure only raises 0.262 ℃, which indicates that the heat dissipation performance has little to do with the thickness of the glass layer. When changing the airflow rate of the surface of the device to make the convection coefficient increase from 25 W/(m2·K) to 85 W/(m2·K), the temperature of luminous layer of traditional encapsulation structure decreases from 42.911 ℃ to 26.85 ℃, which has a remarkable impact on reducing the temperature of the active layer.