The invention belongs to a production method of humic acid iron compound fertilizer. The method comprises steps as follows: (1) performing wet ball-milling on weathered coal or lignite to obtain coal slurry, sending the coal slurry into a dosage bunker, adding a sodium hydroxide or potassium hydroxide solution with the mass concentration ranging from 5% to 12%, evenly mixing and sending the mixture to an extraction tank, heating the mixture at the temperature of 80-90 DEG C for 20-30 min, uploading the mixture into a sedimentation tank for solid-liquid separation, and concentrating a supernatant; (2) adding an iron source to a humic acid solution prepared in Step (1) with stirring for a reaction at the temperature of 50-80 DEG C for 3-7 h, filtering and drying a product to obtain humic acid iron solids, wherein the mass ratio of the iron source to the humic acid solution is 1:(20-30); (3) adding filler and a plant growth regulator to humic acid iron obtained in Step (2), and evenly mixing the mixture to obtain a mixed material; (4) adding the mixed material obtained in Step (3) to molten fertilizer, and performing granulation, drying and screening to obtain the humic acid iron compound fertilizer product.