Polyacrylonitrile (PAN) solution was electrospun into fibrous membranes with nonwoven structure and quasi parallel fibrous structure Using a rotating drum collector. Surface fluorination treatment technique was applied to transform the intrinsically hydrophilic PAN membranes into hydrophobic membranes. A set of surface fluorination treated electrospun PAN membranes were tested for membrane desalination (MD) using a lab-scale air gap membrane desalination system. The results show that it is promising to use intrinsically non-hydrophobic membranes in MD after surface fluorination modification based on permeate flux and salt rejection ratio. In the MD application, we found that the fiber orientation combing with the flow direction of the feed could affect the mass transfer performance. The quasi-parallel fiber alignment, surface fluorination treatment, liquid entry pressure, permeate flux, and mass transfer coefficient Were studied in detail in this work.