Abstract: In order to design guided mode resonance gratings with reflection function, based on equivalent medium theory, planar waveguide theory and rigorous coupled wave analysis, theoretical analysis and experimental verification were carried out, guide-mode resonance gratings were designed to realize reflection resonance on 850nm (TE).The effects of grating parameters, incident angle and thickness of waveguide layer on resonance wavelength and linewidth were calculated by rigorous coupled wave method.The results show that, with the increase of duty cycle, resonance wavelength will shift red and resonance linewidth increases first and then decreases with the increase of duty cycle.When duty cycle is 0.5, line width can reach the widest.Resonant wavelength increases with the increase of grating period and waveguide layer thickness.But the line width is almost unchanged.When the period increases from 490nm to 520nm, resonance wavelength is red-shifted by nearly 50nm.When the thickness of waveguide layer increases from 217nm to 251nm, resonance wavelength is red-shifted by nearly 25nm.The influence of grating thickness on resonance wavelength and resonance linewidth is very weak.When the incident angle is perpendicular, there is only one resonance peak.But when the incident angle is not 0°, there will be two resonance peaks.And with the increase of incident angle, one resonance wavelength will be blue-shifted while the other will be red-shifted.This study provides theoretical guidance for practical preparation of reflective guided mode resonance gratings.