<p>We proposed a low threshold and wavelength tunable plasmonic coupled nanolaser based on an Au@Ag nanoparticle dimer / Ag film coupled structure. The optical cross section of the plasmonic nanolaser based on the coupled nanostructure can be 34 times larger than that based on a single Au@Ag nanoparticle (NP). And the corresponding loss compensation threshold of the plasmonic coupled nanolaser is only 25.3% of that of the nanolaser based on the single Au@Ag nanoparticle. This is attributed to the fact that the coupled nanostructure exhibits stronger optical confinement and a stronger electric field than the independent nanoparticle. In addition, the wavelength of the plasmonic coupled nanolaser can be tuned from the visible to the near-infrared region by adjusting the Au@Ag NP size, the particle-particle gap distance, and the particle-film gap distance. Furthermore, the multi-wavelength emission can be achieved and tuned by adjusting the gain coefficient. This work contributes to advancing miniaturized and integrated nanolasers for on-chip applications and provides a promising strategy for designing multi-wavelength plasmonic devices.</p>