The invention discloses an evaporation and concentration device for a cellosolve NMMO (N-methylmorpholine-N-oxide) aqueous solution. The technological process of the device is characterized by comprising series preheating, single-effect feeding, down-flow evaporation and enriched-effect combined heating. The device comprises a single-effect evaporator, a two-effect evaporator, a three-effect evaporator, a four-effect evaporator, a five-effect evaporator as well as a primary preheater, a secondary preheater, a tertiary preheater, a quaternary preheater and a quinary preheater which are only used for feeding of the single-effect evaporator and connected in series for preheating. The invention further discloses an evaporation and concentration technology for the cellosolve NMMO aqueous solution prepared by the evaporation and concentration device for the cellosolve NMMO aqueous solution. With the adoption of the evaporation and concentration technology and device, the NMMO aqueous solution with the concentration being 65% and the vapor-water ratio being 0.215 as well as the NMMO aqueous solution with the concentration being 85% and the vapor-water ratio being 0.225 can be obtained, and the vapor-water ratios are ahead of the national level being 0.23.