A hybrid refractive/harmonic diffractive infrared lens beyond normal temperature was designed. The infrared lens was consisted of three lenses, including one aspheric surfaces and a harmonic diffraction surface which made the lens have compact structure and light weight. The experimental results show that the modulation transfer function is above 0.42 and 0.35 in the temperature range of -120～100 ℃ when the working wavelength in 3.8～4.2 μm and 8.8～11.2 μm, and the efficient focal length is 54.68 mm. It is compatible with infrared dual-color detector which had a format of 320×240 and the pixel pitch of 30 μm.