The picture captured by the remote sensing camera will be degenerated since the camera constantly rotates around the earth. The degenerated image may decrease the focusing accuracy. In order to solve this problem, a method based on the time delay and integration (TDI) pattern of interline transfer progressive scan CCD is proposed. The interline transfer CCD KAI-1003 is used as the imaging device, and PLD is used to control the driving timing signal for the sake of matching the velocity between CCD and object. In this way, the motion blur can be eliminated. The experimental results show that the imaging system not only eliminates the motion blur but also increases the signal to noise ratio (SNR) of the image. After removing the motion blur, an auto-focusing method of remote sensing camera is also proposed, with the feature that the images have overlapped regions captured in a short time. Firstly, the displacement and the overlapped regions of two adjacent images in the image sequences are calculated using the image registration algorithm. Then a sequence of focusing accuracy values through performing a sharpness evaluation function on the overlapped region of each image is obtained. Finally, according to the transfer characteristic, the evaluation value is mapped in a same evaluation system, and the accurate focus position is found. The experimental results indicate that the imaging system works pretty well for auto-focusing when the object moves in a high speed.