Polyaniline is widely used as a kind of conductive polymer. The preparation of polyaniline has been studied mainly by the methods of chemical synthesis and electrochemical synthesis. In this paper, polyaniline was synthesized by chemical oxidation under acidic conditions using ammonium persulfate as oxidant. And then, the polyaniline was doped with a certain concentration of protonic acid to make it conductive. Finally, Nano-cellulose and polyaniline were combined to obtain composite products. The optimum conditions were discussed in the experiment and the composite with good electrical conductivity was achieved. The results shown that the conductivity of the conductive polyaniline was 9.98 S/cm under the optimum experimental condition (reaction temperature was 0 °C, the amount of material APS:AN was 1:1, HCL concentration was 2 mol/L). The best compound effect was that Nano-cellulose and polyaniline were mixed by in situ polymerization and ultrasonic treatment of the combined effect and the composite ratio was 3:2. This work provide a new method to prepare conductive polymer of polyaniline.