The main factors affecting the purity of aphanitic graphite are discussed. This artcle pointed out that quartz, kaolinite, illite, andalusite, sericite and a small amount of impurities such as pyrite, tourmaline, limonite and calcite, are the main factors influencing the purity of aphanitic graphite. This paper introduces the methods of physical purification and chemical purification, which are used in the purification of graphite. The principle, technical features and existing problems of various purification methods above are analyzed. The development of the technology for the purification of the crystalline graphite is prospected. It is pointed out that the purification technology of the crystalline graphite will be in the direction of energy saving, environmental protection and synthesis.