The invention relates to the technical field of constructional 
engineering, in particular to a double-layer 
curtain wall. The double-layer 
curtain wall comprises a wall body and a PLC control cabinet, 
dirt on an outer-layer glass 
curtain wall is washed at 
high pressure by designing high-pressure spraying, a 
shower head type spray head of a hollow layer does not need to be replaced, and the problems that a water absorption 
sponge is wound around the periphery of a scraping and washing device, use has a certain service life, the water absorption 
sponge needs to be changed continuously, and since the water absorption 
sponge wound on the periphery of the scraping and washing device is mounted in the hollow layer, the replacement is inconvenient are solved; by using the interaction of high-pressure spraying and washing and a hot-
air blower, the problems that the water absorption sponge is wound on the periphery of the scraping and washing device, and when glass of the hollow layer is cleaned, water and dust are prone to interacting to generate 
dirt to be left on the glass are solved, and 
drying of the hollow layer is achieved; and meanwhile, the hot-
air blower is started and an upper aluminum 
alloy electric 
shutter and a lower aluminum 
alloy electric 
shutter are closed in winter, and therefore hot air generated by the hot-
air blower is retained in the hollow layer to form 
electric heating, and the use performance of the double-layer curtain wall is greatly improved.