The present disclosure provides a polarized Raman spectrum-based nano barcode smart label, including: a substrate and a nanoparticle coding layer that is provided on the substrate and can be coded by polarized Raman spectrum coding, wherein the nanoparticle coding layer that can be coded by polarized Raman spectrum coding is a mixed layer including a plurality of nanomaterials having different Raman characteristic peaks; under different polarization detection states, the Raman characteristic peaks can exhibit coding characteristics that are totally different from those under a non-polarization detection state and are distinguished from those of a conventional Raman peak position, so as to achieve spectral characteristics for multiple coding. During use of the smart label of the present disclosure, a corresponding nano barcode detection system is used to detect a brand label provided with the encoded nanoparticles to obtain coding information of the brand label.