Abstract: The adsorption behavior, decarbonylation and hydrogenation reaction mechanisms of furfural on best Pd/Cu (111) bimetallic model were investigated by density functional theory method. The results show that the initial adsorption at O₃-Pd-top and O₇-Cu-hcp site is most stable, with the adsorption energy of 73.4 kJ/mol. On the Pd/Cu (111) bimetallic surface, decarbonylation reaction of furfural is more likely to occur. The decarbonylation reaction of furfural has low activation energy. Each steps of decarbonylation mechanism is exothermic reaction. Furfural tends to form (C₄H₃O) CO by losing the H atom from the branch chain, and furan is then formed by decarbonylation and hydrogenation of the intermediate. Throughout the process, the hydrogenation of C₄H₃O is the rate-determining step with the highest activation energy barrier of 72.6 kJ/mol. For the hydrogenation of furfural, reacting with the first hydrogen is the rate-determining step, and it has the highest reaction energy barrier of 290.4 kJ/mol.