NOVELTY - Syngas methanation catalyst comprises nickel oxide, mesoporous gamma alumina modified by cerium oxide as a carrier and transition metals e.g. iridium, lanthanum, copper and iron or oxides of alkaline earth metal e.g. magnesium and calcium as auxiliary materials. The preparation of mesoporous gamma -alumina adopts hydrothermal synthesis and the preparation of the nickel-based catalyst adopts the soaking process.    USE - The catalyst is useful for converting syngas into methane, methanation of carbon dioxide (claimed), and for synthesizing natural gas.    ADVANTAGE - The catalyst: is easy to prepare; comprises mesoporous gamma -alumina modified by cerium oxide as carrier to obtain nickel-based catalyst having high temperature resistance and high anti-sintering property, low temperature activity and high temperature stability and methane selectivity; solves the problem natural gas shortage.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing the syngas methanation catalyst, comprising: (a) dissolving polyoxyethylene-polypropylene- polyoxyethylene triblock copolymer in ethanol, where the mole ratio of the weight of the triblock copolymer and aluminum of aluminum salt is 100-140, adding aluminum isopropoxide, aluminum chloride and/or aluminum nitrate in the solution after the triblock copolymer completely dissolves, stirring for 4-8 hours at 20-40 degrees C, maintaining the temperature at 60-80 degrees C for 48 hours in an oven, roasting at 400-600 degrees C for 4-6 hours to obtain mesoporous gamma -alumina; (b) soaking the mesoporous gamma -alumina in cerous nitrate solution, drying at 100-120 degrees C for 2-3 hours, roasting at 400-500 degrees C for 2-3 hours to obtain cerous nitrate modified by cerium oxide; (c) soaking cerous nitrate modified by cerium oxide in nickel nitrate solution, drying at 100-120 degrees C for 2-3 hours, roasting at 400-500 degrees C for 2-3 hours to obtain nickel loaded catalyst; and (d) soaking nickel loaded catalyst in transition metal and/or the oxides of alkaline earth metals, drying at 100-120 degrees C for 2-3 hours, roasting at 400-500 degrees C for 2-3 hours to obtain loaded nickel based catalyst which is modified by different auxiliary materials.