In view of the influence of continuous changeable orbit heights and satellite velocities on elliptical orbit on the space TDI CCD camera imaging, a vector map analysis method was proposed to calculate the time varying image motion of the elliptical orbit. Through establishing different coordinates, the satellite velocity and target velocity generated with earth self-rotation were transformed from original coordinate to TDI CCD camera image plane coordinate. By taking a critical regression elliptical orbit as an example, the image motion velocity vectors which affect TDI CCD camera imaging and data readout frequencies were calculated. Finally, a three-axis air flotation turntable attitude simulation system and a TDI CCD camera were used in experiment to verify the vector map analysis method. The results show that during one period of satellite on critical regression elliptical orbit, the values of drift angle, image motion velocity and target movement speed are separately -3.76°-3.22°, 0.1673-0.72 mm/s, and 19.12-82.24 pixels/s according to equivalent parameter law. The image collected can satisfy the resolution of the 1-2 pixels, which proves that vector map analysis method is accurate on computing image motion velocity, which is able to provide reliable basis for space TDI CCD camera imaging on the elliptical orbit.