Abstract: In order to improve the problems of traditional digital light processing (DLP) projection system, such as, large volume, complex structure, high cost, and low utilization efficiency of light source, using single three-color light emitting diode as light source and using a novel DLP projection optical structure of forming parallel light by a single lens, the traditional optical path was improved and optimized. Without colorwheel in the traditional optical path, the complex structures of light gathering and light distribution in the traditional projection light path were realized by lens directly.After using TRACEPRO software to model, the projection light path was analyzed by ray tracing. The results show that, the volume of whole optical system is controlled at 76.8mm×32.2mm×25mm, utilization rate of light energy reaches 60.1%, spot uniformity reaches 96.6%, and luminous flux on screen surface is 21.7lm. The research reduces the volume of projection light path, simplifies the optical structure and improves the utilization ratio of light energy.