Restoration to the degraded and blurred image was a key point in remote sensing image processing. In this paper

modulation transfer function（MTF） of the imaging system and the basic theory of MTF was researched. A new method that proximately mensurate MTF of imaging system was presented

and a series of processing technologies such as limited sampling

curve fitting

Fourier transform and normalization and so on were included in this method

so as to get point spread function（PSF） in image acquisition and transmission. A complete and smooth modulation transfer function’s curve was extracted

restoration of deconvolution to source degraded and blurred image was applied in frequency domain

and the restoration result was analyzed and evaluated. This method was applied to Disaster Monitoring Constellation satellite image

the quality of image was greatly improved

and the restoration result is satisfying.