To address the problem of accurately regulating the surface plasmon (SP) characteristics of metal-dielectric nanocomposites,a composite structure with a dielectric matching layer spacing was designed.The numerical relationships between the particle size and spacing of metal nanoparticles,the dielectric constant and thickness of the dielectric matching layer,and the near-field local enhancement and far-field scattering characteristics were studied by finite-difference time-domain method (FDTD).The results show that,in the incident light range of 400—900 nm,the resonance peak of the composite structure redshifts with the increase of gold nanoparticles and the decrease of particle spacing.The energy of the composite structure is highly concentrated in the dielectric matching layer,and when the dielectric constant is between 3 and 5,the coupling of localized surface plasmon (LSP) and propagation SP can be induced,which significantly enhances the electric field strength of SP.Meanwhile,the increase of the thickness of the dielectric matching layer can realize the redshift of the resonance peak.The results in this article verify the reliability of the method to comprehensively regulate the SP through the structure of metal nanoparticles and dielectric matching layer.