Sesquioxides are ideal host materials for mid-infrared laser with high power and energy for their excellent thermal properties, stable physical and chemical properties, low maximum phonon energy and strong crystal field. It is very difficult to prepare large crystals with high quality due to the extremely high melting point of sesquioxides. Researchers have conducted long-term research and exploration on the crystal growth of the sesquioxides. The fast development of laser technology in recent years, which put forward urgent requires for high-quality sesquioxide single crystals, has prompted a breakthrough in crystal growth technology. In this paper, based on the brief introduction of the properties and structures of sesquioxides, the research progress on crystal growth methods and defects of sesquioxides Lu2O3, Sc2O3 and Y2O3 are reviewed in detail. Further, the laser performances of rare earth ion-doped sesquioxides in the mid-infrared band from 1 μm to 3 μm are systematically summarized. Finally, the development of the sesquioxide single crystals in the future is also prospected.