The invention provides an OLED packaging structure and method, wherein the OLED packaging structure comprises: a substrate disposed with OLED device; a first inorganic barrier layer formed on the substrate and covering the OLED device; an organic buffer layer formed on the first inorganic barrier layer, the organic buffer layer being doped with particles having negative thermal expansion coefficient; a second inorganic barrier layer formed on the substrate and covering the first inorganic barrier layer and the organic buffer layer. By doping the organic buffer layer with particles with negative thermal expansion coefficient to form a gradient doping organic buffer layer, the invention can reduce thermal deformation of the organic buffer layer, reduce or even eliminate the thermal expansion and deformation difference at the interface between the organic buffer layer and the inorganic barrier layer, thereby to reduce the film peeling or bubbling probability and improve packaging reliability.