The utility model discloses a lightweight planting roof structure, which belongs to the field of building planting roofs and comprises a roof panel, an isolating layer, a drain board, a filter layer, a planting soil layer and a
green vegetation layer. The upper portion of the roof panel is coated with the
isolation layer, the drainage plate is arranged on the upper surface of the
isolation layer, the filter layer is arranged on the upper portion of the drainage plate, the planting soil layer is laid on the upper portion of the filter layer, and the
green vegetation layer is arranged on the upper portion of the planting soil layer. The planting roof is simplified in structure, light in weight and free of maintenance, construction of the planting roof is facilitated, construction steps and operation processes are reduced, the bearing degree of the planting roof is improved, the variety and the number of planted plants are greatly increased, the depth of a planting soil layer can be guaranteed by increasing the bearing degree, and therefore rooting of
plant roots is guaranteed, and the planting effect is improved. Meanwhile, the water and
moisture retention capacity of the soil layer is improved, the safety of
plant growth is improved, the
survival rate of
vegetation growth is increased, the number and frequency of
plant maintenance are reduced, the use amount of water and
electricity is reduced, and safety is improved.