This paper studied the FTIR spectrum change of alcohol-water system after treated by high voltage electric field (2.0 kV.cm-1, 50 Hz). 4 kinds of systems were studied: pure water, 10% and 50% alcohol water solution and pure alcohol. Results showed that the position of nu (OH) in FTIR spectrum reflect the amount of hydrogen bonds in the alcohol-water system; when the solution treated by 1-30 min, the hydrogen bonds increased first and then decreased a lot. When the 50% alcohol solution and pure alcohol were treated more than 30 min by 2.0 kV.cm-1 electric field, peaks of nu (c-o) and nu (OH)(H2O) appeared in the spectrum. This indicated that alcohol might be oxidized by external physical field force and aldehyde and ester were formed. Test for the treated samples 7 days later found the FTIR spectra were almost the same. Some mechanisms were deduced.