In order to prepare guar gum (GG) nanofibers with the diameter less than 100 nm and solve the difficulty in electrospinning. Cetyl dimethyl ethyl ammonium bromide (EHDAB) was used as surfactant, calcium chloride (CaCl₂) was used as strong electrolyte, and GG nanofibers were prepared by electrospinning. The effects of EHDAB and CaCl₂ mass fraction on the surface tension, conductivity and viscosity of spinning fluid were investigated by contact angle measuring instrument suspension method, conductivity meter and rotational rheometer. Scanning electron microscopy, contact angle measuring instrument seat dropping method and agar flat dish diffusion method were applied to characterize the morphology, water contact angle and antibacterial properties of nanofibers. The results show that solution conductivity, electric field force, and spinning efficiency can be significantly increased by CaCl₂; when the mass ratio of GG, EHDAB and CaCl₂ is 0.9:0.2:0, the average diameter of the fibers is the smallest of 40 nm; the maximum tensile strength of the nanofiber film is 9 MPa, the minimum contact angle is 23°, and the hydrophilicity is good, and the fibers show good hydrophilicity and antibacterial properties.