The invention relates to a preparation method of a bamboo charcoal mask, which belongs to the life field of cosmetic. The preparation method of the bamboo charcoal mask comprises the steps of: A, a decoction solution preparation: according to the parts by weight, weighing 5 to 10 parts of oat powder, 3 to 5 parts of semen sesami nigrum, 5 to 10 parts of soybean, 4 to 6 parts of bletilla striata and 3 to 5 parts of angelica sinensis powder, adding water into oat powder, semen sesami nigrum and soybeans for decoction, filtration and concentration to obtain a first decoction solution, adding water to bletilla striata and angelica sinensis powder for decoction, filtration and concentration to obtain a second decoction solution, and mixing the first decoction solution and the second decoction solution to obtain the decoction solution; and B, preparation of the bamboo charcoal mask: according to the parts by weight, weighing the decoction, 1 to 8 parts of bamboo charcoal powder with particle size of 8,000 to 12,500 meshes, 30 to 40 parts of tea juice, 15 to 20 parts of cucumber juice, 0.5-1.8 parts of peppermint, 3 to 5 parts of egg white and 40 to 50 parts of water, and carrying out microwave vacuum treatment for the components, then, pouring the mixture into a mask mould for cooling, and obtaining a bamboo charcoal mask finished product. The bamboo charcoal mask provided by the invention is capable of preventing aging and reducing wrinkles, strengthening the skin elasticity and clearing up the blockages in the pores.