Abstract: In this paper, the transfer alignment of large misalignment is studied. Loop calibration is used to dissipate the attitude error, and a velocity plus attitude matching transfer alignment method is also designed. Compared with the conventional transfer alignment, the nonlinear error model doesn't need to be established, and the transfer alignment completes quickly using classical Kalman filter. The simulation result shows that the slave INS attitude error is less than 30′by loop calibration, and the attitude precision is 0.5′, the azimuth precision is 2′.