A lithium-sulfur battery includes a cathode, an anode, a lithium-sulfur battery separator and an electrolyte. The lithium-sulfur battery separator includes a PSL and a FL. The FL is located on a surface of the PSL. The FL comprises carbon nanotube structure and a plurality of MoP2 nanoparticles. The carbon nanotube structure defines a plurality of micropores. The plurality of MoP2 nanoparticles is located on surface of the carbon nanotube structure and filled in micropores in the carbon nanotube structure.