The supported copper based catalysts could be potential candidate for the selective catalytic hydrogenation of acetic acid to produce ethanol instead of noble metals. In this work, a series of highly efficient bimetallic Cu-In/SBA-15 catalysts were designed and prepared via the deposition-precipitation method. Detailed characterizations were carried out to investigate the textural properties, dispersion and chemical state of the metals, the interactions between copper and indium species, the adsorption and activation of acetic acid on the catalysts surface. The results clearly demonstrated the coexistence of Cu-In alloy and metallic Cu under the reductive reaction atmosphere. The strong synergistic effect inside Cu-In alloy not only accelerated the dissociation of acetic acid to acetate, but also hindered the combination of acetyl and ethoxy species to form ethyl acetate, thus promoting the catalytic hydrogenation performance significantly. It was also found that the concentration of adsorbed H atoms on catalysts was one of the indispensable factors affecting the ethanol selectivity, which was positively correlated to the exposed Cu surface area and H-2 partial pressure. The optimal catalytic hydrogenation activity was obtained for 9Cu1In/SBA-15 under the reaction conditions of 2.5 MPa and 623 K, the conversion of acetic acid and selectivity of ethanol reached 99.1% and 90.9%, respectively. These results might provide an inspiration in the rational design of novel copper based catalysts for carboxylic add hydrogenation.