Infrared thermal imaging lens and infrared thermal imaging system

The embodiment of the invention discloses an infrared thermal imaging lens and an infrared thermal imaging system. The infrared thermal imaging lens comprises a first lens, a second lens and a third lens which are sequentially arranged from an object side to an image side along an optical axis; the first lens has negative focal power, the second lens has positive focal power, and the third lens has positive focal power; the first lens and the third lens comprise free-form surfaces. According to the embodiment of the invention, distortion and other aberrations can be effectively controlled by using the free-form surface, and the imaging quality is effectively improved. Meanwhile, the free-form surface is used for designing the lens, the design freedom degree is larger, matching of the shape of an actual detector is facilitated, more design resources are saved compared with a traditional circular image surface, the number of lenses is reduced, and the design difficulty and cost are reduced. 本发明实施例公开了一种红外热成像镜头和红