The invention discloses a method for outputting a high-resolution digital image to a microfilm. The method comprises the following steps of: (1) sending a section of non-sensitized 16-millimeter film to an appointed position; (2) processing an image to be shot reversely and dividing the image to be shot into four pieces; (3) sending the divided images to a splicing imaging mechanism batch by batch, wherein the splicing imaging mechanism comprises at least two splicing liquid crystal plates; a front polaroid and a light emitting diode (LED) light source are arranged on the outer side of each splicing liquid crystal plate sequentially; a rear polaroid is arranged on the inner side of each splicing liquid crystal plate; each splicing liquid crystal plate is positioned at a focal length position of the incidence surface of a focusing lens; and the divided images of the first batch are imaged through the corresponding focusing lenses respectively and form a first spliced image; (4) finishing the exposure imaging of the first spliced image; (5) controlling the width of the first spliced image exposed by the precise forwarding of the film until the last batch of the divided images are imaged and a tail-end spliced image is subjected to the exposure imaging; and (6) repeating the steps to finish the integral exposure process. In the method, by timeshare blocked image exposure, the requirement on an image resolution technical index of a digital image microfilm camera can be met.