The invention relates to the field of compound fertilizers, in particular to a coated slow-release compound fertilizer containing oxidized graphene. The fertilizer is prepared from the following raw materials in parts by weight: 10-15 parts of 1,250-2,000-mesh diatomite, 0.1-0.2 part of gibberellins, 20-24 parts of potassium dihydrogen phosphate, 10-12 parts of silkworm excrement, 8-10 parts of sawdust, 15-18 parts of diphosphorus pentoxide, 6-8 parts of sodium polyaspartate, 10-12 parts of a calcium magnesium phosphate fertilizer, 8-12 parts of peat soil, 2-4 parts of ferrous sulfate, 9-13 parts of potassium fulvate, 15-18 parts of decomposed cattle manure, 2-4 parts of withered persimmon leaves, 1-2 parts of sodium molybdate, 10-12 parts of wheat straw powder, 1-2 parts of oxidized graphene, 3-4 parts of fructooligosaccharides, 20-25 parts of waterborne polyurethane emulsion, 1-2 parts of an epoxy silane crosslinker and 4-5 parts of an assistant. According to the compound fertilizer, various raw materials are used; multiple nutritional ingredients are provided; the nutritional ingredients are coated with diatomite and a slow-release coating agent, so that the nutrient loss is hardly caused, the fertilizer efficiency lasts for a long time, the crop yield and the crop quality can be remarkably improved, and the planting benefit is relatively high.