The invention provides a perm treatment method with a small wet/dry difference. A first dose of perm is coated, so that hair wound around a bar is swelled and softened the first dose of perm is washed when a chemical spray component (42) moves inside a cover (2), a chemical which contains a salt of an ascorbic acid and is used as an intermediate treating agent is evenly sprayed on the whole hair the hair is warmed by a hair drier (12) meanwhile, the salt of the ascorbic acid is fixed towards the hair wound around the bar and the hair is kept moist, so that a negative pressure state is formed in the bar when the hair is dried by virtue of the hair drier (12), ozone is atomized towards the cover (2) from an ozone unit (3), so that the whole hair is surrounded by the ozone atmosphere the salt of the ascorbic acid on the hair wound on the bar is oxidized oxidation of the salt of dehydrogenized ascorbic acid comes into play and a disulfide bond of the whole hair surrounded by the ozone atmosphere is recombined.
