With the increase of laser power, high-energy laser systems have increasingly demanding requirements for laser exit aperture windows. Magnesium aluminate spinel (MgAl₂O₄) transparent ceramics exhibit excellent optical, thermal, and mechanical properties, making them widely used in infrared guidance windows, high Mach aircraft radomes, and windows for optoelectronic equipment in extreme environments. However, there are relatively few reports on their use as laser exit aperture windows. This article briefly introduces the current state of research and development of magnesium aluminate spinel transparent ceramics for laser exit aperture window applications. Focusing on the most critical performance aspects for this application, the absorption coefficient of magnesium aluminate spinel transparent ceramics currently used in transparent bulletproof armor and aircraft windows are tested. The purity of magnesium aluminate spinel powders prepared by the bimetallic alcoholate method and the magnesium aluminate spinel transparent ceramics produced using hot pressing combined with hot isostatic pressing techniques are analyzed. Furthermore, the factors affecting the absorption coefficient of the ceramics are discussed.