Preparation method of multifunctional biomass carbon potassium fertilizer

Belonging to the technical field of biomass carbon preparation, the invention particularly relates to a preparation method of a multifunctional biomass carbon potassium fertilizer. The method includes the steps of: A. raw material crushing; B. mixing of a biomass raw material with potassium hydroxide; and C. preparation of the biomass carbon potassium fertilizer. The invention is a one-step preparation method of a multifunctional biomass carbon potassium fertilizer by biomass pyrolysis. In the preparation process, potassium hydroxide reacts with pyrolysis generated carbon dioxide, organic acid and the like, the carbon dioxide emission is reduced, and the carbon element in the biomass is captured, so that the purposes of carbon fixation and emission reduction can be realized. The prepared multifunctional biomass carbon potassium fertilizer can be applied to the field to adsorb pollutants in the soil and improve the soil environment, and also can provide the potassium source for a long term, thus realizing green agriculture.