The invention relates to the field of composite fertilizers, in particular to an active microorganism coated slow release composite fertilizer, which is prepared from the following raw materials by weight part: 10-15 of 1250-2000 mesh diatomite, 10-12 of triple superphosphate, 15-18 of potassium dihydrogen phosphate, 20-22 of urea, 18-20 of ammonium carbonate, 10-12 of boric magnesium fertilizer, 14-15 of plant fallen leaves, 7-8 of soy bean residue, 0.02-0.03 of a JT strain, 1-2 of ammonium molybdate, 5-6 of Oenanthe javanica, 1-2 of freshwater shrimp shell powder, 10-12 of crop straw, 8-10 of peanut meal, 1-3 of radix isatidis, 6-8 of fermented chicken manure, 10-12 of porous starch, 1-3 of sodium trimetaphosphate, 4-6 of acrylic acid, 6-8 of polyvinyl alcohol, 0.1-0.2 of ammonium persulfate, 3-5 of cherry stone powder, 2-4 of orange peel, 15-18 of fermented alga liquid, and 4-5 of an additive. The composite fertilizer provided by the invention has wide material sources and comprehensive and rich nutrients, and in terms of the production technology, diatomite and an active slow release coating agent are utilized to form dual coating on nutrients, so that the fertility can be more lasting, and the soil vitality can be improved, plant diseases and insect pests can be reduced, and the efficacy of enhancing crop yield and quality can be achieved.