Scanning beam interference lithography (SBIL) is advantageous to produce large-area linear diffraction gratings that are phase-accuracy to nanometer level. In order to comprehend the merits of SBIL, the research progress on SBIL both in China and abroad are introduced, and the key technologies in SBIL are summarized from the merits and limitation of the scheme and principle. And then for the application of the specific grating, parameters of the key technologies in SBIL are presented. The development of SBIL is forecasted.