Disclosed herein are phage-displayed single-chain variable fragment (scFv) libraries, which comprised a plurality of scFvs with a specific sequence in each CDR. The present scFv libraries could be used to efficiently produce different antibodies with high binding affinity to H1 hemagglutinin of influenza virus. Accordingly, the present disclosure provides a potential means to generate different antigen-specific antibodies promptly in accordance with the need in experimental researches and/or clinical applications.