Sponge greening roof structure and construction method

The invention relates to the technical field of roof greening, in particular to a sponge greening roof structure and a construction method, according to the main technical scheme, the sponge greening roof structure comprises a plurality of sponge units, and each sponge unit comprises a vegetation frame and a reservoir arranged on the lower side of the vegetation frame and used for receiving rainwater; the reservoir is connected to the lower side of the vegetation frame through a channel, a sundry storage box is slidably connected into the channel in a resettable mode, and the bottom of the sundry storage box can be opened and closed; an impurity discharging pipeline is further arranged in the channel; after impurities fall into the impurity storage box, the gravity of the impurity storage box is increased, the impurity storage box slides towards the end of the impurity discharging pipeline, when the impurity storage box is in butt joint with and communicates with the impurity discharging pipeline, the bottom