During the grinding and classification process, some useful minerals that have already been dissociated cannot be separated in time, resulting in overgrinding. Overgrinding can cause metal loss and a decrease in the production capacity of the mill. This study conducted experimental research on flash flotation conditions using a cyclone sand settling device from a gold ore beneficiation plant in Shandong as the experimental sample, using advanced techniques such as process mineralogy analysis. The results showed that the recovery rate of pyrite was 63.18%, the recovery rate of pyrite monomers and metal sulfide symbiosis was 90.94%, the gold grade of the concentrate was 110.61g/t, and the recovery rate was 71.12%. For the sand settling sample of the cyclone, flash flotation can achieve efficient pre recovery of pyrite monomers and metal sulfide symbiotes, which is of great significance in avoiding continuous circulation and overgrinding of these minerals in the closed circuit of grinding and classification, and improving the overall recovery rate.