Abstract: In the process of initial alignment for rolling bases, the accuracy of a model and the observability and observability degree of states are important facts to confirm the filtering effect. A fast and precise alignment method for rolling bases was discussed. Considering time-delay between the master and slave inertial navigation system, a precise transfer alignment model of "velocity + pose" matching was established. The observability analysis of piece-wise constant system (PWCS) and singular value decomposition of observability degree were combined, the observability degree of strapdown inertial navigation system (SINS) -s states were analyzed quantificationally, and the optimal estimation of SINS can be received at the three axes rolling state. Consequently, the SINS can achieve the optimal speed and precision of initial alignment performance. The choice of optimal maneuvers trajectory for carriers and the matching mode of transfer alignment can be gained for alignment of carrier weapons. The simulation results validate the efficiency of this method.