The present disclosure provides a packaging assembly and a preparation method thereof, and a display device. The packaging assembly may include at least one of packaging unit; the at least one of packaging unit including a first inorganic layer, a second inorganic layer, and an organic layer sequentially stacked, wherein a material of the first inorganic layer and a material of the second inorganic layer are different. Holes inside the layers may be reduced, and a density of the layers may be increased. An effect of blocking the water vapor may be higher than that of a single layer, and a packaging effect may be better.