Disclosed is a polypeptide binding to a plurality of amyloid monomers and aggregates, characterised in that: the polypeptide contains the amino acid sequences as shown in (a) and/or (b): (a) the general formula of the amino acid sequence is Ser-X1-Phe-X2-Asn-Lys-Arg, wherein X1 and X2 are independently any one of the 20 amino acids； and (b) the variant having the function of the polypeptide and modifying the general formula (a) of the amino acid sequence by the substitution, deletion or addition of one or more amino acid residues. The polypeptide with a small molecular weight can specifically bind to the oligomers of Aβ42, amylin, insulin and lysozyme and the monomers of Aβ42 and amylin, as well as fibres, can inhibit the aggregation of Aβ42 and lysozyme and inhibit the cytotoxicity of Aβ42, amylin, insulin and lysozyme, and can protect the nerve cells from the influence of Aβ42 toxicity, so that same has a wide application prospect in the prevention and treatment of diseases of amyloids like AD, PD, HD, T2DM, etc.
