For structural characteristics of polymer light-emitting diode (PLED) surface light source, thermal model of dual-channel is built. By using finite element analysis software, the thermal properties of PLED surface light source is simulated in the light intensity of 1000 cd/m2, and temperature distribution is obtained under natural convection and forced convection. The simulation results show that the highest temperature is in PFO-BT emitting layer of the PLED surface light source with temperature of 43.934 ℃ and 26.234 ℃ respectively. By simulating the whole process from the beginning to the light intensity of 5000 cd/m2, the linear relation between the highest temperature TH and input power P is gained. By changing the electrode shape and size of aperture opening ratio of PLED surface light source respectively, the influence of these factors on thermal characteristics of PLED surface light source is obtained. The simulation results reveal that the electrode shape is one of the most important factors to the highest temperature TH of PLED surface light source, and using circular electrode can promote the dissipation of heat of PLED surface light source effectively. As the aperture opening ratio increases, the highest temperature TH of PLED surface light source increases steadily, but they do not present a simple linear relationship. These results provide a basis for the optimization of PLED surface light source.