The invention discloses a titanium-containing hydrated alumina composition and a preparation method thereof, and a molding body, a preparation method and applications thereof. The titanium-containinghydrated alumina composition contains hydrated alumina, a titanium-containing compound and a compound having at least two proton acceptor sites, wherein the [phi] value of the composition is less than5. The present invention further discloses a catalyst using a molding body formed from the titanium-containing hydrated alumina composition as a carrier and having hydrogenation catalysis effect, anda preparation method thereof, and a hydrotreatment method. According to the present invention, the high-strength molding body is prepared by using the hydrated alumina wet gel as the starting raw material, such that the hydrated alumina wet gel drying step is eliminated, the total process is simplified, the total operation energy consumption is reduced, the dust pollution caused by the application of the pseudoboehmite dry glue powder as the raw material is avoided, and the working environment is greatly improved; and the catalyst using the molding body prepared from the hydrated alumina composition as the carrier has high catalytic activity in the hydrotreatment of hydrocarbon oils.