The model of the optical priciple error, the cross sensitivy error and the error induced by temperature were built. These errors have affected the measurement precision of a fiber optic accelerometer which can be used to measure the direct current signal of acceleration. With a purpose of obtaining the exact data, the simulation and experiment were conducted. Results show that, the measurement errors of interrogation algorithm decrease with the signal-to-noise ratio increasing and the spectrum sampling interval shortening, and the measurement accury is 4.5×10－5; under the effect of one time gravitational acceleration, the cross sensitivity error is 1.8 mg; the scale factor will increase(decreas) 0.79‰ when the temperature rises (drops) 1℃.