The invention discloses a preparation method of a non-refrigerating type infrared light detector. The preparation method is characterized by comprising the steps of providing a substrate; manufacturing and forming a first electrode layer on the substrate; manufacturing and forming an absorption layer on the first electrode layer; manufacturing and forming a buffer layer on the absorption layer; manufacturing and forming a transparent electrode layer on the buffer layer; manufacturing and forming a second electrode layer on the transparent electrode layer, wherein the absorption layer adopts anIB-IIB-IVA-VIA doped P type material; and the buffer layer adopts an N type semiconductor material. The preparation method of the non-refrigerating type infrared light detector disclosed in the embodiment is simple in process, relatively simple in needed equipment, low in manufacturing cost, capable of realizing large-area production and realizing civilian use; and in addition, by adopting the IB-IIB-IVA-VIA doped P type material to manufacture the absorption layer, infrared absorption wavelength can be expanded.