The invention discloses a polypyrrole/metal nanocrystal/ high polymer nanofiltration conducting film preparation method, including the steps of 1, dissolving a polymeric stabilizer and a surfactant inan organic solvent to obtain a solution, adding nano-particles into the solution and performing ultrasonic dispersion; 2, adding polymer precursor in solution obtained in the step 1, stirring and cooling; 3, adding pyrrole monomer with mass fraction being 1-10% into solution obtained in the step 2, stirring, standing to obtain casting solution; 4, forming a flat membrane with thickness ranging from 100 micrometers to 300 micrometers by scraping the casting solution; 5, placing the flat membrane obtained in the step 4 into phase inversion solution which contains an oxidizing agent. Nanofiltration conducting film prepared by the method has high conductivity (500-5000 S/m), can intercept dyestuff and organisms of which molecular weight is higher than 400, and has pure water flux (10-30L/(m<2>.h.bar)) which reaches or higher than that of common nanofiltration membrane, and accordingly has wide market application prospect.