This paper researches on calibration algorithm of skewed installation laser gyros and quartz accelerometers. Based on the analysis of the skewed installation principle, the error models of laser gyro and quartz accelerometer are established. The skewed installation calibration algorithm based on the least square is designed by using the marble slab and rate turntable. The proposed algorithm eliminates the design link of complex calibration tooling to reduce the error accumulation and has advantages of high precision, small residual error,cost effectiveness. With the calibrated error parameters compensated in the navigation software, the laser inertial measurement unit with laser gyro′s accuracy of better than 0.05 (° )/h and quartz accelerometer′s accuracy of better than 5×10-5g0(g0=9.8 m/s2) has achieved the navigation precision of 10 min static navigation precision of better than 10 m and 6 min dynamic navigation precision of better than 40 m. This result fully meets the requirement of parameters separation for engineering applications to high precision laser inertial measurement unit.