The invention discloses a preparation method of 
biomass porous carbon, which belongs to the technical field of a functional material. The preparation method comprises the following steps: mixing and ball milling 
vinasse, 
starch and glycerin, and obtaining ball milled uniform 
slurry; mixing and fermenting the ball milled uniform 
slurry, 
cryolite, modified additives, Carbomer, 
gum Arabic solution, adding aluminum 
chloride solution which is 0.2 to 0.3 times of the 
mass of the ball milled homogenous 
slurry, stirring and mixing, dropwise adding a 
sodium hydroxide solution, adjusting pH to 10.3 to 10.6, 
drying, pulverizing, screening, and obtaining a blank; gradually heating the blank in a 
nitrogen atmosphere, electrifying, reacting at the high temperature, cooling, and obtaining a carbonized blank; and mixing the carbonized blank and water according to a 
mass ratio of (1:10) to (1:20), soaking the carbonized blank, filtering, and 
drying, thus obtaining the 
biomass porous carbon. The biomassporous carbon provided by the invention has excellent specific surface area and 
porosity.