The present invention relates to a high speed image sensor based on a low speed CCD, which is characterized in that the structure is that an adjustable diaphragm is closely arranged in front of the light sensation of the low speed CCD which has a adjustable drive circuit and a peripheral circuit, and the output terminal of the CCD is connected with a denoising circuit and a module transfer circuit in sequence. The exposure region of the CCD light sensation area is controlled by the diaphragm, the CCD chip is driven by the special adjustable circuit, only the electrical charge of the CCD pixel unit of the exposure part is transferred, the electrical charge transferring time can be reduced obviously, and the frame speed of the CCD is improved. The present invention has the advantages that the structure is simple, the reliability is high, the cost is low, the measuring speed is rapid, and the precision is high, thereby the present invention is suitable for the real-time detecting in the fields of manufacturing industry, image recognition, automatic precision measurement, robotvision, and automatic following, etc.