Method for preparing butanediol by carrying out two-stage catalytic hydrogenation on butynediol

The invention relates to a method for preparing butanediol by carrying out two-stage bed catalytic hydrogenation on butynediol. Aiming at the requirements on the suitability for a reaction system which contains water or fluctuating water content in a process for preparing the butanediol by carrying out two-step hydrogenation on the butynediol, and the inhibition on the generation of carbon deposit, the inventor proposes that: a hydrogenation catalyst A and a hydrogenation catalyst B in a two-stage bed respectively contains a carrier, a metal active component and silane groups, further, the silane groups are grafted through a silylanizing treatment, wherein the content of the silane groups in the total weight of the hydrogenation catalysts is 0.1-12 wt%. Compared with the prior art, under the premise of ensuring that the hydrogenation catalysts have better activity and better selectivity, the method provided by the invention has obvious raw material suitability, and the presence of water hardly influences on the catalytic performance of the hydrogenation catalysts; and meanwhile, the generation of the carbon deposit on the surfaces of the catalysts can be obviously inhibited, and the service life of the catalysts is prolonged, so that the hydrogenation reaction system can have a longer stable running cycle.