Cellulose/multi-walled carbon nanotubes (MWCNTs)- composite membranes applied in electrochemical and biomedical fields were prepared using 1-ethyl-3-methylimidazolium diethyl phosphate (EmimDEP) as solvent in this study. With the increasing of MWCNTs amount, the membrane conductivity increased, and the conductivity reached 9.1 S/cm as the mass ratio of MWCNTs to cellulose being 2:1. The additions of sodium dodecyl sulfate (SDS), 1-hexadecyl-3-methylimidazolium bromide (C(16)mimBr) and 1-butyl-3-methylimidazolium tetrafluoroborate (BmimBF(4)) efficiently improved the conductivity, mechanical property, and thermal stability by promoting the dispersion of MWCNTs. When the mass ratio of C(16)mimBr to MWCNTs changed from 0 to 0.3:1, the conductivity increased from 0.08 S/cm to 0.14 S/cm, and the tensile strength increased from 13.3 MPa to 17.0 MPa. These results indicate that the binary ionic liquids (ILs) system can regulate the properties of the composite membranes, and is a feasible approach for preparing cellulose/MWCNTs composite membranes with enhanced properties.