The invention belongs to the technical field of air purification and particularly provides a bio-based degradable efficient air-filtering fiber membrane material. This air-filtering fiber membrane is made by means of static spinning from bio-based polymer soy protein and polyvinyl alcohol as main materials and one or more of water-soluble natural polymer derivatives such as methylcellulose, chitosan and hydroxyethyl cellulose, as auxiliary materials, wherein the diameter of nano fiber is 100-1000 nm, the thickness of the fiber membrane is 20-1000 micrometers, and the fiber membrane is up to higher than 65% in porosity, 10-100 nanometers in pore size and up to higher than 90% in filtering efficiency. The bio-based degradable air filter membrane can be processed to serve for various purposes such as masks, screen windows and air purifiers, is safe and reliable and is low in cost; meanwhile, the preparation method is simple, the requirements on equipment is low, the production cost is low, the obtained air filter membrane has good filtering effect and high absorbing capacity, is degradable and recyclable and has promising market prospect.