The ore processed by a gold ore dressing plant in Zhenyuan,Yunnan,is microfine disseminated low-grade refractory gold ore.Due to the lower gold grade of the run-of-mine ore,the flotation index is not satisfactory.The grade of gold concentrate is around 25 g/t,the gold recovery rate is around 80 %.To further improve the separation index,the optimization test on reagent regime and process structure was carried out.The results show that under optimized optimal reagent regime,when the process of staged grinding and flotation and middling regrinding is used,the gold grade of gold concentrates greatly increases to 41.54 g/t,the gold recovery rate increases to 89.46 %,indicating good index,which can provide a reference for the treatment of microfine disseminated gold ore.