Abstract: Based on the maskless lithography system with DMD, a new IC layout data interface algorithm has been presented, which established the interface from layout data to exposure data. The interface can meet the needs of digital lithography system, using process layer as a unit to convert the high precision IC layout data into the gray data automatically with the same pixel structure with DMD. And the interface are compatible with the two industrial standard IC layout data of GDSII and CIF, which can easily deal with all of the basic graphic element of GDSII and CIF, meanwhile, it also can utilize the method of vector algorithm calculation to succeed in solving the difficult conversion in intersecting, overlapping or some other special composed graphic. After lots of experiment, it's proved that the interface has the capability of low complexity, high precision, and high efficiency. And it can he used as a new efficient passage to be research has practical significance to the production of the LSI.