Improving the yield of large-flake graphite is the research focus in the field of crystalline graphite separation. However, graphite flakes would be seriously damaged by gangues with high hardness during grinding in the conventional multi-stage grinding and multi-stage separation because flake graphite and gangues were always together. Based on this, this paper put forward a new technology and technology for separating gangues and graphite as early as possible by enhanced gravity concentration (EGC), and separating large-flake graphite from fine-flake graphite separately at the same time, which reduced the damage of gangues to graphite flakes during grinding. The experimental results showed that the yield of large flake graphite increased to 4.74% after adopting this new technology. Furthermore, with the help of the atomic force microscopy (AFM) detection technology, the large-flake graphite concentrate obtained by the latest technology was conformed with a lower roughness and more superior performance.