The present invention relates to a method for constructing an Fv library based on a combination of proteins, a method of screening a desired antibody using the constructed Fv library, an Fv antibody screened by the screening method, and an Fv library constructed by the Fv library construction method. The Fv library of the present invention is based on a combination of proteins so that members thereof can be individually analyzed for their function. Moreover, the Fv library enables a desired Fv antibody to be screened without needing a target antigen preparation. In addition, the protein combination based Fv library makes it possible to significantly reduce the number of protein purification processes to thereby reduce costs and time, compared to conventional DNA-based libraries.