The invention relates to the preparing method of an alkanes hydrogenating catalyst. The carrier of the catalyst is gamma-Al2O3, the active ingredient is VIB group and VIII group metals and the active accessory ingredient is Ti. Ti is led in the aluminum hydroxide gel. It adopts second-aging in the stage of gel-forming so it can ensure the uniform disperse of Ti on the aluminum hydroxide surface and larger bore volume, larger specific surface area and larger aperture. The invention adopts complete mix-and-pinch method to prepare the catalyst. The processing procedure comprises the following steps: adding alkaline solution that contains Mo and/or W to the second-aging aluminum hydroxide dry gel powder which contains Ti; mixing and pinching fully until the aluminium hydrate powder is totally sodden by alkaline solution; adding acid solution that contains Co and/or Ni, mixing and pinching until the material is able to be molded; squeezing the materials to be strips; drying and calcinating. Ti spreads more uniformly on the catalyst made in the invention; the function of the catalyst also improves substantially.