The “position+velocity” transfer alignment method is adopted to simulate the impact of two factors, airframe structure deformation and baseline information delay, on the real-time posture accuracy of the Inertial Measurement Unit (IMU) at the Antenna Phase Center (APC).The conversion relationship between main and sub inertial navigation coordinate systems is clarified, and the influence rules of these two types of factors on the real-time posture information of the sub-inertial navigation at the APC after transfer alignment are obtained.The simulation shows that:1) The matching algorithm is not suitable for the case where the airframe has intense dynamic deflection and deformation and with high frequency in deformation;and 2) The baseline information delay may seriously affect the estimation time and accuracy performance of the “position+velocity” transfer alignment.Therefore, it is necessary to make structural deformation compensation and delay compensation and use other measures when the above two factors have serious effects.