The invention discloses a method for preparing a heterogeneous organic metal catalyst Ni/C oxide. A water-soluble nickel salt solution and a low-molecular-weight organic acid solution are mixed and stirred at normal temperature, standing is conducted for 6-8 hours, then a liquid supernatant is removed, sediments are dried at the temperature of 80 DEG C. Pulverization is conducted after drying, the organic metal catalyst Ni/C oxide is prepared by calcining in an air atmosphere in a box-type atmosphere protection furnace. Compared with other technologies, the method is simple to operate and cheap in medicament price and saves cost; the molar concentration of the low-molecular-weight organic acid is controlled to be slightly larger than that of nickel nitrate, so that metal ion residues in a solution can be reduced, and the pollution to the environment is reduced; in the application process of the prepared catalyst, the recycle technology is simple, no complex operation is needed, and the catalyst is low in cost, simple, efficient and environmentally friendly, and has a very broad application prospects and a very large research value.