<p>Unidirectional conductive wet fiber materials are employed in membrane materials because of their directional transport capability. In this study, a Janus membrane with directional transport function was prepared by electrospinning method using cellulose acetate butyrate (CAB) as the main raw material. In order to obtain a hydrophilic nanofiber membrane, the CAB nanofiber membrane was modified to be hydrophilic, and the modified nanofiber membrane was subjected to analysis of membrane density, porosity, contact angle, and FTIR. Finally, the CAB nanofiber membrane was sprayed onto the modified nanofiber membrane using an electrospinning device to obtain the Janus membrane, and its pore structure and single transport capacity were analyzed. The results show that the Janus membrane exhibits a unidirectional moisture conductivity index R of 1037.53, which reaches Level V, and the asymmetric structure and pore size gradient provide the driving force for the unidirectional moisture conductivity.</p>