Abstract: According to the invention, the catalyst contains oxides of nickel (25 per cent by weight), of aluminium (50 per cent by weight), of magnesium (14 per cent by weight), of calcium (10 per cent by weight) and of barium (1 per cent by weight), and the method of preparing it consists in that nickel carbonate, oxide or hydroxide of aluminium, and magnesium oxide pre-calcined at a temperature of 1300.degree..+-.50.degree.C, are mixed with an aqueous solution of nickel nitrate and of barium oxide; the obtained mixture is dried and calcined, and to the obtained mixture of the metal oxides are added a binding agent (calcium aluminate), a lubricating agent (potassium stearate), and a wetting agent (water or an aqueous solution of sulphosalicylic acid or of triethanolamine); the prepared mixture is pressed into tablets and the latter are hardened hydraulically, dried and calcined.The invention can be used in petrochemical synthesis.