The invention belongs to the technical field of methane synthesis catalysts used for coal-to-gas, and concretely relates to a preparation method of a methane synthesis catalyst. The catalyst is suitable for preparing substitute natural gas through coal gasification, and has the characteristics of high stability and difficult carbon formation at a high temperature under high CO content. The preparation method of the catalyst comprises, adopting a stepwise coprecipitation technology, comprises the following steps: adding a magnesium and aluminum soluble salt mixed solution to a sodium bicarbonate or sodium carbonate solution to carry out neutralization and precipitation; adding nickel soluble salt and a mixed solution of soluble salt of one or more of lanthanum, potassium and cerium to the above solution to continuously carry out neutralization and precipitation; and washing the obtained material, filtering the washed material, drying the filtered material, crushing the dried material, roasting the crushed material, granulating the roasted material, carrying out tabletting molding, and roasting the molded material to obtain the methane synthesis catalyst.