The invention belongs to the technical field of 
biology and specifically relates to a preparation method and an application of a nano 
antibody capable of specially binding with an anti-deoxynivalenol 
antibody. The 
amino acid sequence of the nano 
antibody is SEQ ID No. 1. The invention also relates to a 
nucleotide for encoding 
amino acid. The nano antibody is capable of taking the place of the expensive high-
toxicity DON standard substances, and can be applied to the immunological detection of the DON as a competitive 
antigen or a 
solid-phase envelope 
antigen; the nano antibody has immunoreaction characteristic similar to that of natural DON molecule, and is excellent in effect. Compared with the traditional 
antigen mimic epitopes based on polypeptides and the traditional anti-
idiotype antibodies based on IgG, the nano antibody has the characteristics of more stable structure, acid-alkali resistance, high 
temperature resistance, high detection sensitivity and the like, and therefore, the immunodetection stability of the nano antibody is greatly improved, and meanwhile, the 
endurance capacity of the nano antibody to the environment is also improved.