The invention discloses a low-temperature evaporating system. The low-temperature evaporating system comprises a raw water inlet pump, a spraying head water inlet pump, an evaporator, an afterheat condenser, a heating condenser and a compressor, wherein the raw water inlet pump and the spraying head water inlet pump are fixedly connected with a spraying water pond; the raw water inlet pump and thespraying head water inlet pump are positioned on the left side of the spraying water pond; the evaporator and the heating condenser are electrically connected with each other through the afterheat condenser; the evaporator and the heating condenser are positioned on the right side of a spraying chamber through the afterheat condenser; the compressor is positioned below the evaporator and is fixedly connected with the evaporator through a pipe; and the left side of the raw water inlet pump is fixedly connected with a waste water treatment inlet. According to the technical scheme, through the spraying head water inlet pump, water enters a spraying opening on the upper portion, and then is atomized, sprayed and circulated, printing and dyeing waste water can be sprayed in the spraying chamber circularly, the internal activity of the printing and dyeing waste water is maintained, and the purifying effect of the printing and dyeing waste water is improved.