By taking the prism laser gyroscope as the research object and using the finite element analysis method, the problems of the generation and amplification of the residual stress are studied in temperature variation process under the condition of existing scratch on the surface of optical cement. Based on the change of the fused silica's dielectric tensor with stress, the relationship between the stress and gyroscope measurement value is analyzed. The analysis results show that the micro scratch on the optical cement region produces the residual stress in the area whose size is several times of the scratch width, and the frequency division and polarization change are caused. The lock-in threshold of the gyroscope increases, the test precision of the gyroscope and working stability are affected. Finally, by variable temperature experiment, the gyroscope detects the normal angular velocity component of the Earth's rotation, and the combined light spot morphology and precision curve stability are used to verify the correctness of the theoretical analysis.