The invention relates to a metal thio compound @S composite material and its preparation and application in lithium-sulfur batteries, characterized in that it includes a core and a coating material covering the core; the material of the core is sulfur Simple substance; the coating material is at least one metal thio compound with the structural formula on the right; wherein R is a hydrocarbon group, a tertiary amino group or an ether group, and M is Li, Zn, Cu, Cd, Ca, Bi, Pb, Ni , Sn, Fe, Co or Ag metal elements, n is the chemical valence of M. The organometallic thio compound has good lithium ion transmission ability, ensures lithium ion transmission under tight coating conditions, and can provide a certain electronic conductivity; the coating layer of the present invention is compared with the existing inorganic coating The layer is more elastic, which can alleviate the volume change during the charging and discharging process of elemental sulfur, which causes the coating layer to break and fall off. The organometallic thio compounds themselves can provide a certain capacity.