Common organic volatile solvents would volatilize in air, thus causing air pollution and harming human health. Deep eutectic solvents (DESs) are one type of the green solvents with low volatility, deemed as the new solvents of the 21st century. Previous investigation showed that the DESs would undergo volatilization at high temperature and/or vacuum pressure. However, how DESs volatile at ambient temperature and pressure is unknown. Here the volatilization of DESs in air at ambient temperature and pressure was investigated by in situ FT-IR and 2D FT-IR. ChCl (choline chloride):N-methylacetamide was taken as an example of DESs and we found that it underwent severely volatilization even at ambient temperature and pressure. Moreover, the dynamics process of the volatilization was investigated by 2D FT-IR. It was found that N-methylacetamide volatilizes from Chal:N-methylacetamide by destroying the hydrogen bond between free NH group and ChCl in ChCl:N-methylacetamide during the first 60 min. H-bonded NH II with strong H-bonding interaction with ChCl also undergoes a remark alternation at this turning point at ca. 60 min. During the period from 60 and 190 min, there also exists free NH in the DES ChCl:N-methylacetamide. The shift of free NH group ceases after ca. 70 min. After 190 min, most of N-methylacetamide in ChCl-methylacetamide have volatilized, only trace of N-methylacetamide is left, therefore, the shift of IR absorption peaks is negligible. This works shows that we should pay more attention to the volatilization of DESs even at ambient temperature and pressure.