The invention provides an exposure frame data generation method used for dot-matrix maskless photoetching, belongs to the technical field of photoetching and aims at providing an exposure frame data generation method used for dot-matrix maskless photoetching. According to the technical scheme adopted by the invention, the method comprises the following steps: performing graphic processing and data storage; performing time value setting and row vector extraction; performing row vector processing so as to obtain the exposure frame data, wherein the three steps are carried out under the control of the whole exposure frame data generation program flow. According to the method, by virtue of reasonably dividing exposure positions and unifying the exposure positions with exposure time, primary graphs and the divided exposure position are compared, all the exposure positions are assigned as '0' or '1', two-page three-dimensional array storage time value and comparison assigned values are used for extracting the comparison assigned values of all focus points on the exposure positions at the same time so as to constitute one frame, along with the increase of the extraction time value, the exposure position of which the front section is subjected to time value extraction is removed, and the frame data generation velocity is effectively improved.