Abstract: Reflective optical system has characteristics of wide spectrum, no chromatic aberration and small vertical dimension, based on these a two-mirror fivereflection optical system is proposed, which has a wide spectrum of 0.4 m~12 m, long focal length of 1.6 m, overall length of less than 85 mm. High order aspheric surface is introduced into the two reflecting mirrors, and through the aberration balance, the image quality satifies requirement. A new photoelectric conversion material is also used to make the reticle in this system, if the laser beam focus on it, laser energy will excite visible light-long wave infrared spectroscopy, which offers simulated infinity goals for optical axis adjustment of optoelectronic products.