The invention discloses preparation and application of a sulfur-based autotrophic and heterotrophic denitrification nitrogen removal biological filler. According to the invention, the number of micropores and silicon hydroxyl groups on the surface of ceramsite is increased through alkali etching; then the surface of the alkali-modified ceramsite is activated by utilizing high-activity disulfur dichloride; and the disulfur dichloride can be chemically bonded with hydroxyl functional groups on the surface of the ceramsite, so sulfur is loaded onto the surface of the ceramsite to form Si-O-S andcross-linking is performed so as to form a stable net-shaped structure. The sulfur-based autotrophic and heterotrophic denitrification nitrogen removal biological filler provided by the invention canrealize coupling of sulfur-based autotrophic and heterotrophic denitrification, is beneficial for the attached growth of microorganisms, reduces the addition of carbon sources, improves population richness, further increases nitrogen removal efficiency and stabilizes effluent quality.