The invention discloses a one-step preparation method for a supported hydro-desulfurization catalyst, relates to a hydro-desulfurization catalyst, and provides a one-step preparation method for a supported hydro-desulfurization catalyst with simple preparation process and short preparation period. The method comprises the following steps of: mixing aluminum chloride, citric acid and urea, adding solvent into the mixture to obtain solution, adding starch, nickel precursor and molybdenum precursor into the obtained solution, blending uniformly, drying and roasting to obtain the supported hydro-desulfurization catalyst. By adopting the one-step method for preparation, the preparation process is simple, the preparation period is greatly shortened, and the production cost is reduced. In the preparation process, a large amount of water for washing is saved, and sewage discharge is avoided; and the preparation process is environmentally-friendly. The desulfurization rate of the prepared hydro-desulfurization catalyst reaches 96 percent, and the catalyst has good catalytic activity. Moreover, the catalyst has high stability and industrial application value.