Abstract: The gold minerals of a Carlin-type fine-grained disseminated gold deposit in Guizhou oc⁃ cur in sulfide minerals in microscopic-submicroscopic form，and it is difficult to grind and dissociate.In or⁃ der to solve the problems of low gold recovery rate，large circulation load of middlings and high reagent consumption in conventional process，through the whole process investigation，process mineralogy re⁃ search and laboratory test，the combined process transformation scheme of middlings regrinding and recon⁃ centration + step grinding and step separation is put forward，and the industrial test is carried out in two stages.The transformation results show that the gold flotation recovery rate is increased by 3.54 percentage points，the gold concentrate grade is stabilized at about 10 g/t，and the gold grade of tailings is reduced to less than 0.5 g/t.The grinding and classification efficiency is improved，and reagent and the unit consump⁃ tion of energy consumption is significantly reduced. The annual new economic benefit is 20.8359 million yuan，and the static payback period of technical transformation investment is only 0.5 months. This process solves the industry problems of insufficient dissociation and poor early harvest effect of Carlin-type fine�grained gold，which can provide engineering practice reference for the upgrading of similar gold ore dress⁃ ing process.

Key words: Carlin-type gold mine, micro fine disseminated gold, step grinding and step separation, regrinding and reconcentration of middle ore, process transformation, industrial test