In this work, gelatin was dissolved in sodium acetate trihydrate/urea deep eutectic solvent (DES) and then mixed with polyacrylonitrile (PAN) spinning solution to prepare composite nanofiber membranes via electrospinning. The rheological properties of gelatin/DES (Gel/DES) solution and gelatin/DES/PAN (GDES/PAN) spinning solution were investigated. Besides, the water vapor transmittance rate, water contact angle, and antistatic and mechanical properties of GDES/PAN nanofiber membranes had also been evaluated and the composition and structure of GDES/PAN nanofiber membranes had also been characterized by SEM, EDS and FTIR further. Due to the introduction of DES components and gelatin, the composite nanofibers presented a smooth surface, small diameter, uniform distribution and good continuity. GDES/PAN nanofiber membranes also exhibited desirable breathable properties, hydrophilicity, antistatic properties and mechanical strength compared with the PAN nanofiber membrane. GDES/PAN nanofiber membranes would provide new opportunities for the application of gelatin and DES in the electrospinning field.