Compared with other cooled infrared detector material systems, type-Ⅱ superlattice (T2SL) has the characteristics of low cost, high uniformity, good process compatibility, flexible wavelength adjustability and lower Auger recombination rates. As a commonly used and relatively mature energy band structure simulation technology, the k·p method has the characteristics of high computational accuracy and saving computing resources, and has received widespread attention in the simulation of T2SL. The progress of simulation of mid-wave, long-wave, and very-long-wave T2SL infrared detectors was reviewed, and the development process of the k·p method was summarized, as well as the progress and role of the method in the simulation of T2SL infrared detectors, to more intuitively demonstrate the accuracy and convenience of the k·p method in superlattice simulation work. The dark current mechanisms, quantum efficiency, absorption spectra, and other properties of T2SL detectors were discussed with emphasis on the prospect of research and application of T2SL infrared detectors. The k·p method under the approximation of the envelope function can be used to perform accurate theoretical analysis and simulation calculations on the band structure and electronic properties of superlattice materials.