The invention discloses a method for dynamically controlling the reflection spectrum bandwidth of a guided-mode resonance filter and belongs to the fields of optical communication and micro electro mechanical systems. A coupling grating provided by the invention is composed of double equivalent grating bodies with the thickness one half of the thickness of an absentee layer and stacked vertically, for TM polarized incident light, structural magnetic field distribution is changed nearby a Brewster angle by controlling micro/nanoscale relative lateral movement between the two grating bodies, and continuous control of the reflection spectrum bandwidth of the guided-mode resonance filter is achieved. In the lateral movement process of the grating bodies, a peak wavelength shift phenomenon caused by the relative lateral movement between the grating bodies is not obvious, but the reflection spectrum bandwidth changes remarkably, and excellent anti-reflection filtering characteristics of the filter are kept when the two grating bodies produce the relative lateral movement. By finely adjusting an incidence angle, reflection peak shift caused by the relative lateral movement of the two grating bodies can be compensated.