The invention provides a wall surface greening device by adopting a soil-free turf, which comprises a fixing frame, soil-free turf units and an irrigation system, wherein the fixing frame is a reinforcing steel bar grid frame which is fixed with a wall body through connecting pieces; respective soil-free turf units are connected on the reinforcing steel bar grid frame through hooks; the dimension of the soil-free turf units is adapted to the shape of the wall surface; the soil-free turf units are combined by bracket boxes, waterproof coiled materials and soil-free turfs; the bracket boxes are shallow groove shaped structures formed by welding a back plate and two side plates; the soil-free turfs are arranged on the waterproof coiled materials in the bracket boxes; and the soil-free turfs, the waterproof coiled materials and the back plates of the bracket boxes are connected together through iron wires. In the invention, the dimension of the units can be arbitrarily changed to adapt the conditions of the wall surface, upper and lower water flows are smooth, and better irrigation can be realized; moreover, the device has the advantages of adopting simple structure, being convenient to install and disassemble, having light load bearing, and needing low cost, and can be widely applied in the field of the wall surface greening of buildings.