Because of the advantages of simple structure, easy modification, low immunogenicity, good stability, strong specificity and strong affinity, nano-antibodies have broad development space in clinical practice. Compared with traditional antibodies, nano antibodies are easier to store and transport, and after denaturation in high temperature, chemical, pressure and other environments, they can still be efficiently recombined, thereby regaining affinity for antigens. The structure and stability of nano antibody were studied. Multiple DNA sequence repair with the same sequence, easily modified amino acid replacement, protein net charge change, unnatural disulfide bond introduction and CDR supervariable region transfer was used to control the stability of the protein. The implementation of this project is expected to lay a foundation for improving its application in the fields of drug therapy, diagnosis and biosensing.