Surface Plasmon Polaritons(SPPs) is a kind of electromagnetic wave propagating along the interface between metal and dielectric. SPPs has the property of confining electromagnetic wave energy in half wavelength region, which can break through the diffraction limit in traditional optics, and is widely used in the design of subwavelength optical devices. In this paper, the Metal-Insulator-Metal (MIM) structure is chosen to excite SPPs. The MIM structure has a wide spectrum range, supports high group-speed modes at subwavelengths, and enables accurate optical regulation over long distances propagation. In this paper, a MIM waveguide filter based on anchor resonator is designed, the structure is simulated, and the transmission characteristics are analyzed. The simulation results show that the filtering effect at the resonance wavelength changes significantly with the changes of the arc structure angle θ, the rectangular structure height H and the arc structure radius R, and the filtering effect can be precisely controlled by adjusting the corresponding relationship between the parameters fitting data. Because SPPs is sensitive to the refractive index of the medium in the resonator, it can be used to design the refractive index sensor if the anchor resonator is filled with different mediums. In order to explore the influence of structural parameters on waveguide transmission characteristics and further optimize the filter structure, the structural parameters θ, H and R are analyzed, the transmission curve skewing caused by the change of structural parameters is discussed, and the factors leading to the spectral line red shift are expounded. Using the fitting results, high performance narrow band band-stop filters with specific wavelength can be designed. Narrow band band-stop filter is designed based on three windows of multimode fiber. The performance of the three communvication window filters is superior, and the performance is significantly improved compared with other MIM filters. When filtering one window, the normal transmission of the other two windows will not be affected. The communication window selection regulation in optical communication is realized. The sensitivity of the resonance wavelength λ_r to the refractive index n of the medium in the anchor resonator is studied. The simulation results show that with the increase of the refractive index n, the resonant wavelength of each mode is red shifted and the transmission curve is changed. The SPPs coupling in MIM structure is sensitive to the refractive index of the medium in anchor resonator , which can be used to make sensing equipment. Compared with the MIM structure of L-shaped resonator, the sensitivity is improved and it is more suitable for designing medium refractive index sensor. In conclusion, a filter based on anchor resonator is designed in this paper. Simulation analysis shows that the structure parameters θ, H and R of anchor resonator can affect its filtering effect, and the narrow band band-stop filtering under the communication window is realized. When the anchor resonator is filled with different mediums, the red shift of transmission spectrum is caused by the increase of refractive index, which provides a theoretical basis for the design of simple dielectric refractive index sensor by using anchor resonator.