In order to extend visualized detection to near ultraviolet and near infrared waveband for industrial testing, under the requirement of achromatic and passive thermal design, broad-waveband optical system working in 300～1 100 nm range is designed, and prototype for industrial testing is developed. Inverted telephoto construction is adopted to achieve an enough back focal length, and splitting the optical beams into three is achieved by insetting a coating prisms within the back focal length, near ultraviolet, visual and near infrared are imaged in three beams respectly. Reasonably lens material is chose to realize achromatic design. The system is passive thermal by moving a lens. The designed system has a field-of-view of ±3.5°, the effective focal length, F/# , back focal length and total length is 66.5 mm, 3.3 nm, 63 mm and 132 mm respectively. The results indicate that all MTF is more than 0.3 at 50 lp/mm, and a good performances is achieved over a temperature range (－10～+50)℃, the image requirement is met. Prototype exhibit excellent resulting during experiment. The system gathers as much information as possible about the detected objects by extending waveband, and a good advantage is exhibited in industrial and agricultural testing.