Due to the influence of dynamic environment, large coarse alignment errors of strapdown inertial navigation system(SINS) on moving base were produced. To solve this problem, a new coarse alignment in-movement base on generalizing analytic method was presented through transforming the specific force equation and augmenting auxiliary velocities. Simulations were carried out on moving base. The results show that the azimuth alignment accuracy reaches about 0.357° and the level alignment accuracy is superior to 0.006° when the whole coarse alignment time is less than 200 s, which meets the requirement of linear filter for fine alignment. This method is more simple with less calculation. By using this method, the SINS can acquire high accuracy. All these characteristics prove that this method is valuable in engineering application.