Fecha de publicación: 15/03/2022 Fuente: Wipo "olive oil" The invention discloses a melanin hair dye capable of blackening by using amino acid and a preparation method and a use method thereof, the first agent of the hair dye comprises the following components: 1%-3% of 5, 6-dihydroxyindole, 0.5%-1.5% of arginine, 4%-8% of C16-18 alcohol, 12%-16% of olive oil, 0.5%-2% of PEG-7 olive oil, 2%-8% of propylene glycol, 1%-6% of cysteine, 0.1%-0.2% of sodium sulfite, 0.1%-0.5% of ascorbic acid ethyl ether and the balance of water; 0.2%-2% of polydimethylsiloxane, 0.05%-0.1% of guar gum hydroxypropyl trimethyl ammonium chloride and a proper amount of ethanolamine are used for adjusting the pH value to 6-8; and the balance of water. And the second agent comprises the following components in percentage by weight: 5%-15% of hydrogen peroxide, 4%-8% of C16-18 alcohol, 12%-16% of olive oil, 0.5%-2% of PEG-7 olive oil, 2%-8% of propylene glycol and the balance of water. The hair dye disclosed by the invention is natural, environment-friendly and non-toxic, and a blacker hair dyeing effect can be obtained.