The invention provides a method of preparing 1, 3-propanediol by virtue of hydrogenation of glycerol. The method comprises the following steps: carrying out contact reaction on a liquid phase raw material which contains glycerol and continuously flows and a catalyst filled in a reactor in a hydrogen atmosphere under certain reaction conditions, wherein at least a part of glycerol is converted into 1, 3-propanediol, the catalyst takes an SiO2 or HZSM-5 molecular sieve as a carrier and Re and Ir as main active ingredients, and Re and Ir, serving as main active ingredients, are loaded on the carrier simultaneously or are sequentially loaded in a way that Re is loaded before Ir. Compared with the prior art, the method provided by the invention has the advantages that a novel economical and environmental-friendly catalyst is adopted, and the process is simple, glycerol is selectively converted to 1, 3-propanediol under the conditions of certain temperature and hydrogen pressure, and the process of preparing 1, 3-propanediol by virtue of direct hydrogenation of glycerol is good in economical efficiency.