The inertial concretionary generalized analytic coarse alignment has been widely used in initial alignment of moving base in SINS. Based on the alignment principle, the alignment error was analyzed from two aspects: measuring errors and calculation errors. The error propagation of gyros in the generalized analytic coarse alignment was analyzed compared to the propagation in the traditional analytic coarse alignment. The analysis results were verified by the simulation test. The disturbed acceleration in the real system had a badly impact to coarse alignment accuracy. An optimized scheme with lowpass filter and adaptive criterion was proposed to clear the linear vibration interference. The test showed that the optimized scheme could get higher alignment accuracy.