The invention provides a quick single-lens calculating imaging method based on frequency domain matrix decomposition. In a frequency domain, a frequency domain matrix of a to-be-solved blurred image is disassembled into linear combination of a series of bases. Image restoration calculation is performed on each base and bases corresponding to obtained clear images are saved. Then a new blurred image is also disassembled into linear combination of a series of bases and a final image restoration effect can be obtained through the bases of the obtained clear images. According to the invention, multiple iterative optimization processes in a prior image restoration algorithm are saved and the method is a novel breakthrough of the image restoration field. Required calculation time is reduced substantially and requirement for real time performance of single-lens calculation imaging can be met generally.