Optical SINS error accumulate over time,as an error compensation technique,discrete calibration is a necessary means to improve navigation accuracy. SINS calibration parameters are mainly the scale factor、installation angle and bias, the article described IMU calibration principle, derived the transmission way of calibration parameters errors, theoretically analyzed the correlation effects of the calibration parameters, and get the following results: Bias repeatability errors have no effect on the scale factor and the installation angle calibration; Scale factor linearity and repeatability errors have no effect on the installation angle and bias calibration; Bias stability errors have effect on calibration of scale factor as well as installation angle ; Angle random walk has effect on the gyroscope three calibration parameters; Random noise has effect on the accelerometer three calibration parameters; Asymmetry of the calibration scale factor has effect on installation angle and bias of gyro;Installation angle repeatability errors have effect on bias and no effect on scale factor calibration of gyro ,and have no effect on scale factor or bias calibration of accelerometer.The conclusion is of great significance for INS performance evaluation, error allocation and device selection.