A Long Wavelength Infrared(LWIR) wide-angle lens whose Field Of View(FOV) is 110° was proposed. The operating wavelength of the lens is a range from 8 to 12 μm, the operating temperature range is -40℃~60℃, the effective focal length is 5mm, and the F number is 2. This design utilizes a combination of 6 lens elements that are made of chalcogenide glass materials, Zinc Sulfide, and Zinc Selenide. The optical powers of the lens elements as well as their locations were carefully calculated and optimized to simultaneously eliminate the chromatic and thermal aberrations for the designed wavelength/temperature range. Taking advantage of the superior molding capability of chalcogenide glasses, the proposed design incorporates three aspherical surfaces on lens elements fabricated with chalcogenide glasses, such that optical aberrations can be furtherly corrected. According to the design results, the proposed system can produce thermal images with a close to diffraction limited performance for the temperature range from -40℃ to 60℃. At the spatial frequency of 15 lp/mm, the Modulation Transfer Function(MTF) values of the proposed system are higher than 0.4 for the entire FOV, and at the same time, system distortion is controlled below 5%.