Chitosan (CS) has been studied worldwide including applying in membrane science recently. Although it has so many advantages, some drawbacks also exist, such as its weak mechanical property and low solubility hampered its development. Herein, CS with various deacetylation degree (DD) film and CS/poly(ethylene oxide) (PEO) blend film (PEO with different molecular weight) were prepared, and vapor-crosslink technique was applied to crosslink various CS based membranes using glutaraldehyde. With introduction of polyethylene oxide into CS, the blend membrane surface would transform from a dense structure to a porous structure. The formation of networks in cross-linked CS/PEO membranes by glutaraldehyde decreased pore size, as well as the thermal stability of cross-linked CS/PEO. Besides, a gradual increase of the tensile strength with increasing the cross-linking time initially happened. Our work exhibits the great potential of CS-based membrane modified by PEO and glutaraldehyde.