The invention discloses an intelligent textile finishing agent with convertible surface hydrophilicity and hydrophobicity and a method for preparing the intelligent textile finishing agent. The intelligent textile finishing agent comprises effective components which are perfluoroalkyl group azobenzene acrylic ester copolymers. The method includes carrying out esterification reaction on perfluoroalkyl group azophenol and acryloyl chloride to obtain acrylic ester monomers with perfluoroalkyl group azobenzene; polymerizing the acrylic ester monomers, hydroxyethyl methacrylate and butyl acrylate by the aid of emulsion to obtain acrylic ester copolymer emulsion with the perfluoroalkyl group azobenzene. The perfluoroalkyl group azophenol is used as an initial raw material. The intelligent textile finishing agent and the method have the advantages that the usage of initiators is increased during emulsion polymerization, obtained copolymers are low in polymerization degree and have short molecular main chains, and molecular chains are low in twining degree, accordingly, side group azobenzene is high in molecular isomerism capacity, and the surface hydrophilicity and hydrophobicity can be advantageously converted; reaction conditions for preparing the intelligent textile finishing agent which is an intelligent water repellent finishing agent are mild, processes for preparing the intelligent textile finishing agent are simple and convenient, and accordingly the intelligent textile finishing agent and the method are suitable for industrial production.