A mold and a method of manufacturing GOS ceramic scintillator by using the mold are provided. The mold comprises: a female outer sleeve having a cavity disposed inside; a plurality of female blocks disposed inside the cavity, the plurality of female blocks being put together to form a composite structure having a vertical through hole; and a male upper pressing head and a male lower pressing head, wherein each of the male upper pressing head and the male lower pressing head has a shape consistent with that of the vertical through hole. The disclosure may reduce defects of the related art in hot-pressing-sintering such as a mold has a short retirement period and a high material waste, significantly reduce the cost for production of the GOS ceramic scintillator, and significantly improve a process economy.