Ethanol solution as a disinfectant has been widely used in various fields. However, it has a significant bactericidal capability only when the volume fraction of ethanol is around 70%-75%. For such high concentration of ethanol solution, it has an irritating smell. When it is used for applications such as wound disinfection, it causes a stinging sensation. Low concentrations of ethanol solution are less irritating, but it is also less effective at killing bacteria. In this study, an idea for producing a green, efficient and less irritating disinfectant is proposed. It is based on a plasma-activated low-concentration ethanol solution (PAES). It is found that the plasma-activated 10% volume fraction of ethanol solution can kill more than seven orders of magnitude of Escherichia coli, while the untreated 10% volume fraction of ethanol solution has no bactericidal effect. Besides, the PAES's activity remains unchanged after being stored at -20 degrees C $-20\!\!{}<^>{\circ}\!\!\mathrm{C}$ for three days. Further investigation shows that new compositions including peracetic acid, peroxynitrite, hydrogen peroxide and acetic acid are detected in the PAES, which together are playing the main role of the excellent and prolonged bactericidal effect.