Preparation method of high-temperature methanation catalyst applicable to preparation of methane by reacting CO and CO2 with hydrogen

The invention discloses a preparation method of a high-temperature methanation catalyst applicable to preparation of methane by reacting CO and CO2 with hydrogen. A carrier of the catalyst is an MgO-Al2O3 spinel carrier or a multi-element inorganic oxide compound carrier which consists of MgO-Al2O3 spinel and TiO2; an active ingredient of the catalyst is Ni which exists in the catalyst in a form of nickel oxide; an auxiliary ingredient of the catalyst is La2O3 and/or CeO2; the active ingredient in the catalyst is added in two steps through a kneading method and a dipping method. The preparation method has the beneficial effects that one part of Ni is firstly added through the kneading method, so that the high-temperature stability of the catalyst can be guaranteed; the other part of Ni is loaded through the dipping method, so that the low-temperature high activity of the catalyst can be guaranteed; the catalyst is burned at the temperature of 480-600 DEG C to generate magnesia-alumina spinel, so that the energy consumption and the cost are reduced.