The invention discloses a production method for a biological organic fertilizer which belongs to the field of manufacturing of composite fertilizers. The production method comprises the following steps: with pig manure, cow dung, chicken manure, sheep manure, vinasse, vinegar residue, cassava residue, furfural residue, uncontaminated river mud, corn straw, peanut straw, rape straw, a cottonseed cake, plant ash, a deodorant, a biological nitrogen fixation bacterium, a phosphate solubilizing bacterium, a potassium solubilizing bacterium, a nodule bacterium and a phosphorus activator used as raw materials, carrying out tank continuous fermentation to allow the raw materials become thoroughly decomposed; carrying out deodorizing and removing water; and carrying out granulation to obtain the granular biological organic fertilizer. The fertilizer has the following advantages: a complete range of nutrient elements, capacity of improving physical and chemical properties of soil and enhancing water retention, fertilizer retention and fertility supplying capacity of the soil, no corrosion and damage to roots and seedlings and capacity of substantially improving the quality of an agricultural product.