The localized surface plasmon resonance (LSPR) response of single core-capped non-spherically-symmetric nanoparticles with different structural parameters is calculated based on the three-dimensional finite-difference time-domain method. The SiO2@Au core-capped nanoparticles are prepared by the template method and the vacuum evaporation technique. The surface morphologies and optical properties are measured and analyzed by the transmission electron microscopy and the UV-visible near-infrared spectrophotometer. The effects of structural parameters such as metal shell thickness, core-shell ratio, core diameter and metal surface coverage on the LSPR peak absorption wavelength and absorption cross section are obtained. The results indicate that a small change of the structural parameters of core-capped nanoparticles results in a broadband red shift of the LSPR peak in the visible to near infrared spectral range.