With the rapidly development of optoelectronic technology and computer technology, the projection display technology has also been unprecedentedly developed. In this paper, a zoom projection objective lens is designed based on Digital Light Processing (DLP) projection display technology, the 0.47in DMD chip of Texas Instruments is selected in this paper, its resolution is 1920×1080 and its micromirror pitch is 5.4 μm. The optical system uses a 100% offset transmissive projection structure. The working wavelength of the whole zoom projection lens is visible light, and 14 lenses including protective glass are used for the projection lens, each lens in the designed system is spherical, the total length of the system is 220mm, the aperture of the optical system is about 58mm, focal length of the zoom projection lens ranges from 25mm to 32 mm, viewing angle ranges from 41 degree to 51degree, and F number is 1.7, the distortion of the designed system is less than 3%, the projected image plane relative illumination of the zoom projection lens above 90%, the telecentricity of the system is less than 1 degree. The MTF value is close to 0.3 at the Nyquist frequency 93 lp/mm for the full field of view, the designed system meet the requirements of projection. In order to meet the current processing level, the radius of curvature tolerance, the spacing tolerance, the eccentricity tolerance and the tilt tolerance are analyzed. The results show that the zoom projection lens is easy to process and produce. © 2020 SPIE. All rights reserved.