Abstract: It is the method of pulse count that can be used to carry out the optical detection with CCD,and it is said that each pulse denotes a pixel,so the detective resolution only have one pixel.Although the detecting resolution can be enhanced by increasing the amplification and diffraction radio,the detective resolution only achieve micron level,since the existence of the aberration,spherical aberration effect,In order to improve CCD's detective resolution ulteriorly,a new method of multiple-sampling is brought forward in this paper,With the method,the detective resolution can be raised to the level of sub-pixel.