To compensate the temperature drift in a Fiber Optic Gyro (FOG),a linear multi-variable model was proposed. The model was composed of the autoregression part and the polynomial distributed lag (PDL) part. The former represented the effect on FOG’s current output by its own lags,while the latter described FOG’s drift caused by temperature variation. Due to the linear character of the model,its coefficients were obtained by using least-square estimation method. In the testing,two FOGs' field temperature drift data sets were collected to validate the effectiveness of the proposed model. The results show that the linear multi-variable model is effective,and the FOGs’ accuracy may be improved by more than 50% after compensation.