Roof greening system and working method thereof

The invention discloses a roof greening system and a working method thereof, and relates to the technical field of greening, the greening system comprises a base and a planting cavity arranged at the upper end of the base, a planting plate is arranged at the upper end opening of the planting cavity, a sponge cavity is arranged below the planting plate, a water storage sponge is placed in the sponge cavity, and the water storage sponge is arranged in the sponge cavity. A water outlet for water drainage is formed in the right side of the sponge cavity, and a protective net for preventing soil loss is laid on the surface of the planting plate. The device is designed according to existing needs, the water storage operation can be completed, the water saving effect can be achieved, the irrigation time can be set according to needs, irrigation of plants can be completed, manual irrigation treatment is not needed, in addition, when rainwater is heavy, shielding can be formed above a planting area, the problem of wat