Provided is a nanofiltration composite membrane, comprising: a supporting layer comprising a polyethylene terephthalate, a polymeric porous layer formed on the supporting layer, the polymeric porous layer comprising a polysulfone and an amphiphilic polymer represented by the formula below:




and an interfacial polymerization layer formed on the polymeric porous layer and the interfacial polymerization layer comprising polyamide which is synthesized by polymerizing piperazine with 1,3,5-benzenetricarbonyl trichloride; wherein, n1, n2, n3, x, and y are integers greater than 0, the molecular weight of the amphiphilic polymer ranges from 90,000 to 200,000, and a weight ratio of the polysulfone to the amphiphilic polymer ranges from 2 to 20. The nanofiltration composite membrane can increase the removal rate of divalent ions and separate substances of specific molecular weights in solutions.