Based on the principle of Local Surface Plasmon Resonance (LSPR), this paper uses the finite element method to study the method of adjusting the resonance wavelength of the silver cone nanoarray. COMSOL simulation software is used to simulate the variation of average electric field intensity near the surface of silver cone nano array with incident light. The results show that the resonance wavelength is related to the period of the array and the refractive index of the environment. With the increase of the period p of the conical array, the resonance wavelength is redshifted. There is a linear relationship between them, and the linear relationship between array period and resonance wavelength can be obtained by fitting according to effective wavelength theory: p=0.97λ+21.244. The variation of radius r and height h of cone has no effect on resonance wavelength. When the period of p is 560 nm, r=120 nm, h=200 nm, and the resonance wavelength peak reaches the maximum. The increase in the refractive index of the environmental medium leads to a red shift of the resonance wavelength, the peak height decreases, and multiple resonance peaks appear.