In this work, DFT simulation method was used to study the adsorption and dehydrogenation of ethanol on Cu/Cr2O3 catalyst. Firstly, the stable configuration of Cu-4 cluster adsorbed on Cr2O3(001) surface was studied. Secondly, the adsorption and dehydrogenation of ethanol on Cr2O3(001) surface and Cu/Cr2O3 were calculated. A part of the charge transfers to Cr2O3 from Cu-4 cluster after Cu-4 cluster is adsorbed on Cr2O3(001) surface. It is easier for Cu/Cr2O3 catalyst to supply electrons than pure copper catalyst. Adsorption energy of ethanol molecules on Cr2O3(001) surface is 0.94 eV, suggesting a chemisorptions process. The adsorption energy of ethanol on pure copper is only 0.34 eV. The interface of Cu-4 cluster and Cr2O3 provides the appropriate ethanol adsorption sites. The adsorption energy of the most stable configuration of ethanol is 0.80 eV, and the adsorbed ethanol molecule bonds with Cu atom. There is a charge transfer process among ethanol, Cu cluster and Cr2O3, which can enhance the adsorption stability of ethanol molecules. In this work, DFT simulation method was used to study the adsorption and dehydrogenation of ethanol on Cu/Cr2O3 catalyst. Firstly, the stable configuration of Cu-4 cluster adsorbed on Cr2O3(001) surface was studied. Secondly, the adsorption and dehydrogenation of ethanol on Cr2O3(001) surface and Cu/Cr2O3 were calculated. A part of the charge transfers to Cr2O3 from Cu-4 cluster after Cu-4 cluster is adsorbed on Cr2O3(001) surface. It is easier for Cu/Cr2O3 catalyst to supply electrons than pure copper catalyst. Adsorption energy of ethanol molecule on Cr2O3(001) surface is 0.94 eV, suggesting a chemisorptions process. The adsorption energy of ethanol on pure copper is only 0.34 eV. The interface of Cu-4 cluster and Cr2O3 provides the appropriate ethanol adsorption sites. The adsorption energy of the most stable configuration of ethanol is 0.80 eV, and the adsorbed ethanol molecule bonds with Cu atom. There is a charge transfer process among ethanol, Cu cluster and Cr2O3, which can enhance the adsorption stability of ethanol molecules.