The invention discloses an oil-water separation net membrane as well as a preparation method and application thereof. The preparation method of the oil-water separation membrane comprises the steps ofsynthesizing a 
copolymer containing a 
polyethylene glycol hydrophilic chain, a dimethylaminoethyl hydrophobic chain, and a 
mussel biomimetic 
catechol group, and dissolving the 
copolymer in an aceticacid /  
sodium acetate 
buffer solution; washing and 
drying the net membrane, immersing the net membrane in a 
dopamine-containing trihydroxymethyl aminomethane solution, taking out the net membrane, washing and 
drying, immersing the net membrane in the 
acetic acid /  
sodium acetate 
buffer solution containing the 
copolymer, and washing and 
drying. The oil-water separation net membrane can be applied tooil-water separation. The oil-water separation net membrane contains a 
polymer modified with a hydrophilic and hydrophobic chain, has super-hydrophilic and super-oleophilic nature in air and super-olephobic nature under water /  super-hydrophobic nature under oil, belongs to a water removal and oil interception mode after being pre-wetted by water, belongs to an oil removal and water intercepting mode after being pre-wetted by oil, improves the utilization efficiency of the separation membrane, and has large 
processing capacity and high separation efficiency.