Type-Ⅱsuperlattice (T2SL) infrared detector has high sensitivity and fast response speed, which is suitable for longer distance imaging and higher speed tracking of moving targets. Quantum efficiency (QE) is one of the key indicators to determine whether the photodetector can achieve high quality imaging, so it is of great significance to improve the QE of T2SL infrared detector. In order to have a more intuitive understanding of how T2SL infrared detector QE can be improved, the methods to improve QE of mid-long wave T2SL infrared detector were reviewed, and the extent to which QE can be achieved under different regulatory means were summarized. The effects of band structure design, absorption layer thickness setting, absorption layer doping type selection and material improvement on QE of T2SL infrared detectors are discussed, and the research status and future development of high QE of T2SL infrared detectors are also prospected.