In terms of analyzing the effect of a ship’s three-dimensional rotations including the roll, the pitch and the yaw on imaging quality of synthetic aperture radar(SAR), the existing literatures only consider the effect when only one-dimensional rotation exists, and do not consider the effect when three-dimensional rotations exist simultaneously. In addition, the existing literatures mainly analyze the effect of the ship rotation on the instantaneous Doppler frequency of a scatterer on the ship, which is not directly related to the effect on SAR image quality. This paper derives two-dimensional time-domain expression of the SAR image and the expressions of azimuth coordinates of ship scatterers when there are only one kind rotation or three-dimensional rotations at the same time. Based on the derived formula, after analyzing the offset of the scatterer on the ship in the SAR image, we analyze the deformation of the whole ship in the SAR image. After analyzing the influence of one-dimensional rotation on SAR imaging, we analyze the influence of three-dimensional rotations on SAR imaging. The research shows that the three-dimensional rotations of the ship introduces envelope error and phase error, which causes the scattering points in the SAR image to be blurred and shift in azimuth, and different scattering points have different offsets, so that the shape of the ship is distorted. The simulation results verify the accuracy of the derived expressions and the correctness of the theoretical analysis.