Initial alignment is a prerequisite for the navigation of SINS (Strapdown Inertial Navigation System). This paper introduce a new practical method for initial alignment of a kinematic base using an inertial coordinate system as a reference datum with anti-disturbance initial alignment algorithm without assumption that the initial attitude information is available beforehand with a certain degree of accuracy, briefly introduce the basic principle of this method and verify the initial alignment algorithm of the moving base of the SINS lastly. The result of tests prove that the initial alignment algorithm in this paper has good tracking ability (the maximum alignment time is 30 s; with yaw error less than 0.1°; the maximum heading position error is 0.42% D) with high inertial alignment accuracy which is a solidified inertial system that takes into account the fact that the initial alignment is accomplished under the condition that there are angular wobble disturbances and line wobble disturbances in the wireless motion.