For meeting the requirements of micron printed circuit board (PCB) lithography, a novel PCB projection imaging digital lithography technology which designs and optimizes the double Gauss type structural lithography projection lens based on ZEMAX optical design software has been proposed. The lens has double telecentric structure and can avoid defocus caused by digital micro- mirror device (DMD) deflection. Its resolution is 13.68 mm, numerical aperture NA is 0.045, depth of focus is 200 mm and image plane distortion is controlled strictly below 0.03%. The lens also uses DMD multi-beam inclined scanning technology, rotating DMD with fixed angle round and forming smaller pixel size by utilizing the position of exposure point and light spot overlap integral energy, which raises mesh precision; since this projection imaging technology is based on lithography experiments proving feasibility of the projection imaging technology, besides integer pixel, the noninteger pixel line width can be obtained and image resolution and production can also be improved by controlling mesh precision.