The invention relates to a preparation method for soluble IFN-epsilon protein. The method comprises the steps of PCR amplification, enzyme digestion and connection, IFN-epsilon protein expression and protein purification. The method solves the problem that when a large amount of IFN-epsilon protein is expressed in vitro, soluble IFN-epsilon protein with natural activity cannot be obtained; the soluble IFN-epsilon protein is obtained successfully and prepared into a polyclonal antibody to provide a theoretical basis and experimental guarantee for deep research on biological characteristics of the IFN-epsilon protein and the pathogenic relation between the IFN-epsilon protein and common diseases such as vaginitis and cervical cancers.