Generally, bio organic fertilizer does not need granulation, especially the solid microbial fertilizer which adsorbs a large number of bacteria is not suitable for granulation. Even in the production of fertilizer granulation machine, spraying active microorganisms on the surface of organic fertilizer, a considerable number of active microorganisms will be lost in the process of granulation or drying. Factory granulation is generally to add a binder to the fertilizer, such as clay, so that the fertility of the product is diluted. There are only three situations in which fertilizer granulation machine is needed for bio organic fertilizer: one is large-scale mechanized operation in which fertilization process is carried out simultaneously with Mechanized Sowing. Generally, the soil is not covered completely or not, and non granulated bio organic fertilizer is easy to be blown to one side of the field by strong wind, resulting in uneven fertilization. The bio organic fertilizer is made into round particles which are easy to be mechanically applied. The second is paddy field fertilization. The bio organic fertilizer is put into water and transplanted before ploughing into the soil. As a result, the bio organic fertilizer floats on the surface of the water and fluctuates with the wind, resulting in uneven fertilizer effect. The use of granular fertilizer can make the granular fertilizer sink evenly at the bottom of the water. Third, the organic-inorganic compound fertilizer needs granulation in the production process. Because the chemical fertilizer in the organic-inorganic compound fertilizer is heavier than that in the organic fertilizer, and their specific gravity is different, if they are not granulated and mixed in the same packaging bag, the chemical fertilizer and the organic fertilizer can not be used evenly due to the turnover in the process of storage and transportation.