Abstract: This is an eassay in the field of process mineralogy. Using optical microscope, chemical multi-element analysis, chemical phase analysis, X-ray diffraction, scanning electron microscopy-energy spectrometer and other comprehensive methods, the process mineralogical characteristics of a pegmatite lithium beryllium ore were studied. The mineral composition, chemical properties, symbiosis relationship of minerals, particle size distribution of main minerals and connection growth characteristics in the ore were ascertained. On this basis, the occurrence state of valuable elements such as lithium and beryllium in the ore and the mineralogical factors affecting the recovery of valuable elements such as lithium and beryllium in the ore are described, which provides a basis for the beneficiation work of the mine.