In order to implement high accurate and large dynamic test tasks of inertia measurement unit (IMU), 6-degrees of freedom electric dynamic test table of IMU was designed on the basis of Gough-Stewart platform. Error model was established and the effect of electric cylinder length error on the accuracy of the system was analyzed. The passive spiral increment motion of electric cylinder produced in the movement of IMU dynamic test table was analyzed further and the compensation algorithm of the movement was studied. The quantitative analysis of the error brought from the passive spiral increment motion shows that the effect of the motion to the pose accuracy of dynamic test table is significant. In order to clear the effect, the compensation algorithm was accomplished and was applied to the real-time control system of the dynamic test table of IMU. Experimental results show that the position accuracy of dynamic test table of IMU reaches the design specification due to compensation algorithm.