ing at the problems of traditional mechanical gratings, such as unadjustable period, low detection accuracy and inability to realize continuous spectral scanning, a low-voltage direct current driven tunable nanograting based on composite material made of graphene (GNP) and polydimethylsiloxane (PDMS) is proposed, and the overall structure of grating is designed. The effects of grating structure size and driving voltage on grating period and film temperature are studied by using COMSOL Multiphysics software. The analysis results show that the maximum temperature change of film is about 160 ℃ and the maximum tuning amount of grating period is 160 nm within 5 s under low-voltage driving. Moreover, the changing laws of grating period and film temperature are similar under different driving voltages, which meets the different detection requirements for industrial gases.