Optical voltage sensors face the problem of temperature stability. Based on the Pockels effect model of BGO crystal and the thermo-optic effect and so on, the temperature response model of the optical voltage sensor under the action of multi-physical fields is derived and the spectrum analysis of the output signal is carried out to obtain the effect law of temperature on the output of the sensor, i. e. , the output drift caused by temperature belongs to the low frequency component. Based on the Kalman filtering noise reduction, a high-pass filtering temperature compensation method based on spectral analysis is proposed to improve the temperature stability by filtering out the low frequency components, and calibration experiments and temperature response characteristics are conducted. The experimental results show that the accuracy of the output voltage measurement is better than ±1. 79% in the temperature range of [0 ℃ , 50 ℃ ], and the method is easy to implement and effectively suppresses the influence of temperature drift when compared with the BP neural network temperature compensation method in the same platform.