A new tip-enhanced Raman scattering(TERS) model was established by finite difference time domain (FDTD) method, which included a conical tungsten tip with concave arc and silver-coated and a gold nanoparticle. The enhancement effectandparameter optimizationof the TERS model wereinvestigated. Under 632.8 nmwavelength laser excitation, three-dimensional electromagnetic simulations were carried out forthe TERS effect with different conditions, and the simulation resultswerepresented and discussed. The results indicate thatthis TERS model has the maximum field enhancement factor when the incident angle is 72°, the sample diameter is about 140 nm and the tip sample gap is reach 2 nm. The conclusion provides a reference for developing higher efficiency enhancingmetal tips and the Raman spectrometer with best performance.