Abstract: With the development of LED technology, the trend that LED supersedes traditional lamp as the dominant light source for projectors is gradually obvious, especially for micro-projector. The TIR lens optimized in design are adopted to collect and transform the light from LED to overcome the disadvantage of big volume of an optical system using the tapered light pipe or CPC in traditional projection system. A time-sequence illumination system is designed to take RGB LED as its light source and single LCOS panel as the basic structure. Considering the effect of the time-sequence illumination way, the optical performance was evaluated by the ray tracing simulation program. The result shows the luminous efficiency of the entire system is 2.38%, the volume of the entire system is 125cm3, and the compact structure meets the requirement of illuminators.