To narrow the single-channel bandwidth of the comb filter and increas e the utilization rate of limited frequency band resources,a surface plasmon polaritons (SPPs) interference co mb filter was proposed in this paper.A significant increase in pass band transmittance ,narro wing of the single-channel bandwidth and channel numbers was achieved by this filter.To ex plore the physical mechanism and optimize the filter structure,the effect of the structural parame ters of the comb filter on the transmission spectrum was numerically simulated by finite difference time domain (FDTD) method.Experiment result shows that the single-channel ultra-narrow bandwidth of the comb tr ansmission spectra results from dual interference of SPPs and graphene microca vity.As a result,the comb transmission spectra are mainly concentrated in the near-infrared bands (1 —1.24 μm).By optimizing the structure parameters,the single-channel bandwidth can reach 4.2 nm,and the number of channels is 18.Additionally,the adjacent channel spacing,single-channel b andwidth and channel numbers can be selected by adjusting the width of the silica top layer.Particul arly the comb channel is excited by its material coupling resonance in the filte r,which means that it is simple and more suitable for on-chip integration.