The invention relates to a greening structure of a tall building outer wall. The greening structure comprises corridors attached to the tall building outer wall and accessory structures in the corridors, the accessory structures are used for planting of wall climbing plants to green the tall building outer wall, the corridors are arranged on the tall building outer wall every 3-5 floors, the corridors are formed in the mode that floor stabs inside the wall are picked outwards along with cantilever beams to the outside of the wall by 900 mm, cultivation grooves are formed in the sides, close to the outer wall, of the upper surfaces of the corridors along the wall, the cultivation grooves are 350 mm wide and 400 mm deep, and light cultivation media are contained in the grooves and used for planting of the wall climbing plants; handrails with the height of 1400 mm are installed on the outer sides of the corridors, and the distance between the outer sides and the cultivation grooves is not less than 400 mm. The greening structure is simple and reasonable, the problems that fixed planting places are difficult to find for the wall climbing plants and high altitude greening projects are not convenient to manage when the wall climbing plants are used for greening the tall building outer wall are effectively solved, and a new path is opened up for tall building greening; accessory facilities can be conveniently installed and constructed in the corridors; construction and maintenance cost is low; the wall cannot be damaged, and no negative effect is caused to living environments.