Antimony is an important strategic metal resource. Stibnite as one of the main sources of antimony resources, efficiently recycling stibnite has always been a topic of interest. Currently, there is a scarcity of research examining the adsorption differences of butyl xanthate (BX), sodium diethyldithiocarbamate (DDTC) and ammonium dibutyl dithiophosphate (ADD) on the stibnite (010) surface with Cu2+ activated based on atomic scale. This study investigates the adsorption differences of BX, DDTC and ADD on the stibnite (010) surface with Cu2+ activated, combining density functional theory with experiments. DFT calculations showed that there are five adsorption sites of Cu2+ on the stibnite surface, analysis of partial density of states (PDOS) indicated that the difference in hybridization strength between Cu 3d and S 3p orbitals caused discrepancy in adsorption sites performance. Analysis of PDOS, Mulliken population and electron density difference, it can be concluded that the collector interaction strongly with the stibnite surface with Cu2+ activated and the difference of charge transferred by S atoms during the interaction process is the main reason for the differences in adsorption performance and the varying stability of CuS bonds in adsorption models. Under comprehensive comparison the flotation experiments and adsorption tests showed that with Cu2+ activation, the recovery rate of stibnite was significantly improved with DDTC and the adsorption effect was optimal. Finally, the adsorption performance sequence on Cu2+ activated stibnite surface for the three collectors is as follows: DDTC > ADD > BX. This study combining experimental and DFT calculations, provides guidance for the development of efficient collectors for stibnite flotation in the future.