A hair treatment method comprising steps 1 to 5 to be performed in the following order: 1. a step of applying a first composition to hair, wherein the first composition is acidic and comprises one or more selected from the group consisting of glyoxylic acid, glyoxylic acid hydrates, glyoxylates, and glyoxyl amides 2. a step of leaving the hair having the first composition applied thereto to stand 3. a step of heating the hair with a high temperature heating device 4. a step of applying a second composition to the hair, wherein the second composition comprises substantially no oxidizing agent and has a pH of 9.0 or more and 5. a step of leaving the hair having the second composition applied thereto to stand.本發明提供一種毛髮處理方法,其包含將按以下順序進行之步驟1至步驟5: 1.將第一組合物塗覆於毛髮之步驟,其中該第一組合物為酸性且包含選自由乙醛酸、乙醛酸水合物、乙醛酸鹽及乙醛醯胺組成之群的一或多者; 2.使其上塗覆有第一組合物之毛髮靜置之步驟; 3.利用高溫加熱裝置加熱毛髮之步驟; 4.將第二組合物塗覆於毛髮之步驟,其中該第二組合物實質上不包含氧化劑且pH值為9.0或更高;及 5.使其上塗覆有第二組合物之毛髮靜置之步驟。無
