The invention provides hair moistening and dyeing paste as well as a preparation method and an application thereof, and belongs to the technical field of hair dyeing and caring products. The hair moistening and dyeing paste comprises the following materials in parts by weight: 9-17 parts of henna, 4-10 parts of salvia miltiorrhiza, 9-19 parts of indigo naturalis, 8-17 parts of bletilla, 3-7 parts of rice bran, 3-11 parts of raw ginger juice, 4-13 parts of chrysanthemum, 2-8 parts of mint, 1-5 parts of lemon juice, 8-16 parts of black sesame, 2-7 parts of honey, 2-9 parts of olive oil and 13-25 parts of distilled water. The hair moistening and dyeing paste provided by the invention contains multiple active ingredients and is rich in vitamins and multiple trace elements with hair caring and dyeing effects, capable of activating the self-healing function of hair while dyeing the hair, protecting hair and effectively covering white hair, prepared according to a pure natural formula and long in persistent effect; by adopting the hair moistening and dyeing paste, rebound and color losing are difficult to occur, and the dyeing is realized once; the dyed hair is black and shiny. The hair moistening and dyeing paste is simple in a preparation technology, convenient to use and carry, safe, effective and low in cost and has multiple effects of hair care, hair dyeing, hair growth and the like.