The present invention provides a device and method for sulphur cycle-based advanced denitrification of wastewater coupling autotrophic denitrification and heterotrophic denitrification, and belongs to the technical field of wastewater treatment. The unit generating hydrogen sulfide during the wastewater treatment process adopts a lye to absorb hydrogen sulfide; the absorbed sulfide is introduced into an anoxic tank that removes nitrate nitrogen through sulfur-based autotrophic denitrification; and the remaining organic matters in the anaerobic methane-producing reaction tank are subjected to heterotrophic denitrification in the anoxic tank, and the anoxic unit combines the sulfur-based autotrophic denitrification with the heterotrophic denitrification of organic matters. The coupling of sulfur-based autotrophic denitrification and heterotrophic denitrification strengthens the removal of nitrate nitrogen. The biogas desulfurization process system only absorbs hydrogen sulfide and uses the absorbed sulfide in an anoxic system to realize the recovery and utilization of sulfur.