To solve the problem of the low accuracy of the fiber optic gyroscope (FOG), which is influenced by the bad temperature stability of FOG that the parameters are changed, a new static synthetically compensation method is proposed. Thinking of the property of the temperature, the scale factor nonlinearity and the null-bias drift of FOG, a novel model is researched, which is related to factors of operating time, temperature and input angular rate. The model orders are identified using the classification fitting method. Based on a great deal of tests of temperatures and input angular rates, error-compensation iterative algorithm is proposed. The test results show that the compensation algorithm is effective at full temperatures and full rotate rates, which eliminates the influence of temperature and nonlinearity of FOG.