A porous chitosan/PEG/carbon nanotubes (CNTs) membrane with nanometer scale pores and good distribution was prepared by mechanical blending. Scanning electron microscope (SEM) images showed that 30~50 nm pores with homogeneous distribution appeared on the membrane when CNTs was added, and the porosity increased with the increase of CNT content. Methyl orange adsorption experiment showed that the adsorption quantity of the membrane increased first, and then decreased with the increase of the CNTs content. Copper sulfate solution filtration experiment showed that the water transport behavior of the membrane was improved with the addition of CNTs. At first, the water flux of membrane increased with the increase of CNTs content, but when CNTs content reached a certain value, the water flux decreased. The rejection rate of Cu2+ increased with the increase of CNTs content at first, and when CNTs content reached a certain value, the rejection also decreased.