Abstract: The disclosure provides application of sulfated polysaccharides in resisting novel coronavirus, belonging to the technical field of biomedicine. It is confirmed in the disclosure that by binding to an S protein on the surface of the SARS-CoV-2 virus, the sea cucumber polysaccharides, fucoidans or carrageenans can prevent cell membranes of body cells from adsorbing and internalizing the SARS-CoV-2 virus, thereby preventing the SARS-CoV-2 virus from infecting the body cells, which indicates that the sea cucumber polysaccharides, fucoidans or carrageenans have the effect of prevention and treatment of pneumonia caused by the novel coronavirus. These polysaccharides can be used to prepare protective articles having functions of prevention and treatment of novel coronavirus infection, for example: inhalations, hand lotions, oral liquids and respirators.