The invention discloses a preparation method and application for a high-efficiency sulfate ion adsorbing material. The preparation method mainly comprises the following steps of: 1, performing crosslinking modification on natural polymer polysaccharide chitosan to prepare ternary cross-linked chitosan, and performing loading modification on the modified chitosan resin to prepare ternary cross-linked and loaded chitosan. The material is used for adsorbing the sulfate ions and has a good adsorption effect; and the material has the characteristics of degradability, biocompatibility and environment-friendliness of natural chitosan and is a novel adsorption material which has development potential.