Laser gyroscope is an optical gyroscope with broad application prospects on inertial navigation field. When the application environment of laser gyroscope changes, its performance will be affected. When the temperature changes, the laser gyroscope’s core part - ring resonator cavity will have thermal deformation, so the position of the mirror on the ring resonator cavity will simultaneously change. This will result in the change of optical path, then affect the performance of laser gyroscope. Therefore, it is necessary to study the effect of temperature to the ring resonator cavity. In this paper, the temperature field and the coupling field of the ring resonator cavity of laser gyroscope are simulated and analyzed on the ANSYS Workbench 14.0 platform. The temperature field distribution and deformation of the ring resonator in different temperature environments are studied. According to the simulation results, with the increase of temperature, the deformation of the ring resonator increases linearly in the fixed direction. In addition, the influence of the parameters of the ring resonator cavity on the deformation is studied. The material of the cavity—glass-ceramics’s deformation is linearly related to linear expansion coefficient and Young’s modulus. However, its correlation with thermal conductivity, density and Poisson's ratio is not obvious.