The invention relates to a method for preparing alcohols by selectively hydrogenating aldehydes, belonging to hydrogenation technologies. In order to meet the requirements of people on two aspects, i.e. the improving of the selectivity on preparing the alcohols by hydrogenating the aldehydes and the prolonging of the service life of a catalyst currently, the method proposes that: the aldehydes are taken as raw materials; the
reaction temperature is 20-300 DEG C; the reaction pressure is 0.1-7.0 MPa; the
weight space velocity of the aldehydes is 0.02-20 h<-1>; the aldehydes and
hydrogen gas are in contact with a hydrogenation catalyst; and the aldehydes are produced into corresponding alcohols through selectively hydrogenating. In the method, the hydrogenation catalyst comprises a carrier, a
metal active component and
silane groups; the
silane groups are grafted through a silylanizing treatment; and the content of the
silane groups in the total weight of the catalyst is 0.05 wt% to 25 wt%. Compared with the existing method, with the adoption of the catalyst in the method provided by the invention, the selectivity is high, the amount of byproducts, such as ethers, esters and acetals is greatly lowered; and meanwhile, the generation amount of
carbon deposit is little, so that the catalyst has longer service life.