Abstract: The nano polyaniline/polyacrylate (PANI/PA) composite material with superior mechanical property and stable thermal performance was obtained through studying dispersion and polymerization process of the nano-polyaniline in aqueous acrylate emulsion, and then application area of the nano-polyaniline was extended. Firstly, dispersion stability of the nano-polyaniline doped by different acids in the aqueous acrylate emulsion was studied by the pre-emulsification dispersion technology and analyzed through observing lamination under static stations in this paper. After that, the PANI/PA composite emulsion was synthesized by in-situ emulsion polymerization and were analyzed with conversion and coagulation rate as indexes to optimize polymerization process. Furthermore, physical & chemical and application properties of PANI/PA composite material were researched through testing the TEM, size distribution, thermal performance, et al. The results indicate that: the best dispersion quality belongs to H₂SO₄-doped polyaniline and the maximum dosage can reach more than 1%; The optimum polymerization conditions of PANI/PA composite emulsion are as follows: initiator dosage is 3500-4000 mg·kg⁻¹, emulsifier dosage is 1.5-1.75 g/100 g, acrylate monomer content is 35%-40%, MMA∶BA is 50∶50-55∶45; Moreover, the PANI/PA composite latex particles possess more irregular morphology and wide size distribution with increasing dosage of polyaniline, and appropriate dosage is 0.5%-1%; The thermal performance (DSC, TGA) and tension testing of the PANI/PA composite membrane indicate joining nano-PANI to improve tensile strength and heat resistance of the composite material, thereby eliminating sticky defect of the pure-polyacrylate polymer under high temperature.