In order to study the waterproof properties of nanofiber membranes and explore the mechanism of the influence of the microstructure of the membrane surface on the membrane properties, polyure-thane(PU)/polydimethylsiloxane(PDMS) nanofiber membranes were prepared by electrospinning method with high spinning PU and fluorinated low surface energy PDMS as raw materials. The PU/PDMS particles were deposited by electrostatic spray on the fiber membrane substrate, leading to the creation of an environment-friendly waterproof and moisture permeable membrane. The morphology, waterproof properties, air and moisture permeability and mechanical properties were tested and analyzed. The results showed that the superfine fiber links formed by electrostatic spray formed a star like topological structure, and formed a stable membrane structure with the PU/PDMS nanofiber substrate, with improved waterproof and mechanical properties. When the electrostatic spraying PU/PDMS mass fraction is 6% and the time is 2 h, the nanofiber membrane shows the best water repellency. Under this conditions, the static contact angle of the water reaches 149.1°, the moisture permeability is 5 566.7 g/(m2·d), the air permeability is 11.50 mm/s, the breaking strength is 8.22 MPa, and the elongation at break is 247.1%.