An olefin saturation hydrogenating method for reformed oil includes that under the presence of catalyst, the reformed oil is in contact with hydrogen, the condition of contact is temp. 50-200 deg.C, pressre greater than 0.1MPa, fluid hourly speed 0.1-20 h(-1), and ratio of hydrogen to oil greater than 30; the mentioned catalyst contains a porous carrier material and one VIII family metal and one or two elements selected from boron and phosphorus, the mentioned VIII family metal with the presence of non-crystalline alloy mode and loaded in porous carriers material, the content of VIII famityand boron and/or phosphorus is 0.1-60 wt.%, and the atomic ratio of VIII family metal element to born and/or phosphorus is 0.5-10.