Organic-inorganic compound fertilizer

The invention discloses an organic-inorganic compound fertilizer, which comprises a lignite nitrification humic substance, an inorganic fertilizer and a granulating adjuvant, wherein the organic humic substance is more than or equal to 10 mass percent; the mass ratio of the organic nitrogen/inorganic nitrogen is 1:1-1.2; the mass ratio of carbon/nitrogen is 1:10-30; the sum of nitrogen, phosphorus and potassium is more than or equal to 25 mass percent; and free water is less than or equal to 10 percent. Lignite is oxidized by nitric acid and then a humic acid raw material is extracted; the humic acid and fulvic acid content is obviously improved; the production cost of the humic acid fertilizer can be reduced; and resources are saved. The organic-inorganic compound fertilizer can improve soil nutrient condition and granular structure and meet the requirement of crop growth.