In order to analyze space camera image motion change regulation with time caused by the spacecraft vibration, based on the NASA Landsat-4 satellite platform vibration test results on orbit, focal plane disturbance force model which is a linear combination of continuous spectrum and harmonics of nonstrictly integral multiple of fundamental frequency is proposed. The corresponding domain model of focal plane disturbance force is deduced, based on rigid body kinematics, space camera focal plane image motion model of linear combination of continuous spectrum and harmonics of nonstrictly integral multiple of fundamental frequency is established. Experiment proved the correctness of the image motion model caused by spacecraft vibration.