The invention discloses a lithium-sulfur battery cathode material, and belongs to the technical field of lithium-ion batteries. The lithium-sulfur battery cathode material of the present invention is compounded by porous carbon and sulfur. The porous carbon is composed of an internal core and an external shell. The internal core is of a mesoporous carbon structure. The external shell is of a micro porous carbon structure. The sulfur is filled in the holes of the mesoporous carbon structure and the micro porous carbon structure. The invention also provides an electrode slice and a battery based on the cathode material. The mesoporous structure in the porous carbon has a large pore volume, and can support sulfur of a large weight. The micro porous structure of the outer layer of porous carbon carries sulfur of small molecules. Thus the porous carbon can effectively prevent dissolution of polysulfides in the charge-discharge process, and has excellent cycle stability when the cathode material is ensured to have a high specific capacity.