In order to effectively purify cooking fumes, the root-like fluffy nanofibrous composite nonwovens were fabricated through co-solvent electro-spinning by adjusting the ratio of polyester (PET) and cellulose acetate (CA). The morphology, surface and interface wettability and oil fume filtration performance of as-prepared nanofibrous nonwovens were analyzed via scanning electron microscope, contact angle tester and automatic filter material test system. And the results showed when the mixing ratio was 8:2, it had obvious root hair-like structure. The root tip was 100nm and the root cap was 300nm. Not only is the porosity 93.85±1.71%, but the bulk density is as low as 0.023±0.008. Super hydrophobic (Water contact angle 154±1°) and super oleophilic special surface wettability (Oil wetting time is 2s). The simulated cooking oil fume filtration test shows that the filtration efficiency reaches 92%, and the filtration pressure drop is only 36Pa. After 20 cycles of testing, the filtration efficiency basically does not decrease, and still remains above 91%.After 100 min continuous filtration test, the filtration efficiency is still more than 90%, and the filtration resistance rises regularly, meeting the requirements of cooking oil fume filtration.