In the article considered the control of reagent conditions of flotation copper-nickel ores, it is proposed to take into account in the control algorithm residual ion concentration of sodium dimethyldithiocarbamate (DMDK) in the pulp. Flow control DMDK based on the residual concentration of its ions in flotation pulp provides optimized reagent conditions and improves the qualitative rate of enrichment copper-nickel ores with the simultaneous reduction of material costs for the implementation of the operation.