The invention relates to a method for preparing a 
nitrogen-doped multi-dimensional 
hierarchical porous carbon material with high specific surface area and high pore volume. The 
nitrogen-doped multi-dimensional 
hierarchical porous carbon material is used as a 
sulfur positive 
electrode carrier adaptive to an aluminum-
sulfur battery. The preparation method comprises the following specific steps: 1, preparing a 
polymer precursor with 
high nitrogen content through amine-
aldehyde condensation 
polymerization; 2, carbonizing the precursor under the actions of high-temperature volatilization of 
zinc salt and the like to prepare a 
nitrogen-doped multi-dimensional 
hierarchical porous carbon material; 3, optimizing the pore channel structure of the nitrogen-doped three-dimensional hierarchical pore carbon material through 
potassium hydroxide etching; 4, loading elemental 
sulfur into the nitrogen-doped multi-dimensional hierarchical 
porous carbon through a sublimation method to form a composite positive 
electrode; 5, preparing a positive 
pole piece of the aluminum-sulfur battery; 6, performing battery 
assembly and performance evaluation. The 
discharge capacity of a battery assembled by the aluminum-sulfur battery positive 
electrode material prepared by the method and 
acetamide / aluminum 
chloride electrolyte is kept at 1000 mAh g <-1> or above after 50 cycles at 0.2 A g <-1>, and the 
discharge capacity is kept at 400 mAh g <-1> or above and the coulombic efficiency is kept at 96% or above after 700 cycles at 1A g <-1 >. The preparation method has the advantages of low 
raw material cost, environment friendliness, good structure optimization effect, easiness in modification, good cycle performance of the assembled aluminum-sulfur battery and the like. The method is applied to the field of aluminum-sulfur batteries.