While the amination of primary alcohols to amines is quite normal, the reverse reaction, deamination of amines to alcohols is rare. Recent advances achieve the transformation by catalytic multistep processes. We report a one-pot method that enables water nucleophilic attack of amines through the unique catalytic role of hydrothermal water. By achieving dehydrogenation of amines or building targeting group, we fulfilled amines transformation by subsequent reduction or direct deamination, which could further link to the utilization of naturally abundant glutamic acid. The method avoids oxidants, catalysts or multistep, thus achieves simple, green and selective transformation of primary amines.