The invention discloses a preparation method of mineral printing paste and belongs to the technical field of textile printing dye preparation. Yeast powder is activated in warm water and then is mixed with bentonite and flour, the mixture is kneaded into dough and then left to stand for fermentation, the mixture is fermented to preliminarily activate bentonite, a porous structure is formed, the fermented dough is dried, smashed and calcined, the bentonite is further activated, starch in powder is carbonized, modified bentonite powder is obtained, shredded kelp and a biogas liquid are mixed and fermented and then are soaked with a sodium carbonate solution, effective organic ingredients in the shredded kelp are dissolved and subjected to suction filtration, filtrate and modified bentonite powder are mixed, earthworms eat the mixture, the mixture is converted into water-stable aggregate and discharged in a faeces form, finally, earthworm cast is dried and ground into powder, and the mineral printing paste is obtained. The mineral printing paste has high color yield and good color fastness, and a prepared printed product touches well and has broad application market.