Abstract: The problem of aligning the ship-borne weapons SINS to the reference INS under the conditions of low mobility with the help of waves roll or shake fins was studied in order to make it achieve transfer alignment without a special maneuver. Kalman filtering technology was adopted to estimate the mounting misalignments and ship flexure between the master INS and slave INS. A velocity-plus-attitude matching approach was presented for the shipborne weapons SINS in consideration of the dynamic distortion angle in marine environment, and a high-precision error compensation algorithm for lever arm effect was proposed, thereby the lever arm effects and ship flexure interference in velocity-plus-attitude match-sensitive measurement of shipborne weapons SINS transfer alignment process could be overcome. Simulation results show that the method can realize the transfer alignment of shipborne weapons SINS with satisfactory alignment precision and rapidness under the condition of low maneuver.