In the digital confocal microscopy technology, voltage ceramic is used to drive axial moving of objective lens to collect
image slices, which is simple and flexible, easy to control and will get a large precision. But as a result of the movement,
the corresponding parameters of the system, even the point spread function changes, which will bring error to the image
restoration. According to the principle of optical imaging, the change of the point spread function is quantitative
calculated in this paper, through the experiment of recover the image slices collected by moving objective lens and the
image slices collected by moving the loading platform, the error is calculated, compared and analyzed. The results can
verify the feasibility of moving lens to collect image slices.