An error calibration method for the micro inertial measurement unit( MIMU) which is used for the measurement of stable scanning period parameters of sensor-fused ammunition was proposed in this paper. Due to the movement characteristics of sensor-fused ammunition during the stable scanning period, the measurement range of the gyro is larger, so a special model was built. In the first place, special models for both the gyro and accelerometer of the MIMU were built. Afterwards, the turntable rate experiment and the turntable place experiment were carried out. The linear fit method and least square method were used for solving the experiment data; the parameters of the error model were acquired. Finally, the calibrated MIMU was applied to the simulation bomb-drop experiment. The experiment results indicate that the mentioned error calibration method is rational.