In this paper, the influences of different structural parameters on the radiation enhancement of metal nanometer surface plasmons are studied to increase the coupling efficiency of the incident electromagnetic wave and the free electron of metal surface. The numerical simulation of Au and Ag nanoparticles is carried out, the local field enhancement of metal nanoparticles with different shapes are compared, the spherical metal nanoparticles have more prominent local field enhancement effect compared to other structures. Therefore, Purcell analysis is carried out by the change of the parameters of spherical metal nanoparticles. The results show that the size of long axis along the polarization direction, the size of short axis perpendicular to polarization direction, refractive index of environment materials as well as the distance of nanoparticles apart from the light source can greatly change the effect of metal nanometer surface plasmons resonance radiation enhancement, and they have great influence on the location of the resonance wavelength. Finally, the metal nanoparticles with ellipsoid shell structure are simulated. It is found that as the change of refractive index of the filling medium and the nuclear shell thickness, the radiation intensities are increased in different degrees.