The invention discloses an organic-
inorganic compound fertilizer and a preparation method thereof. The organic-
inorganic compound fertilizer comprises the following raw materials in parts by weight: 25-30 parts of 
green algae, 12-17 parts of 
humic acid, 7-12 parts of 
bagasse mortar, 8-12 parts of 
saw dust, 7-15 parts of 
vermiculite, 5-10 parts of 
filtration mud, 5-10 parts of 
yeast organic waste water concentrated liquid, 5-8 parts of 
cane slag, 2-5 parts of sugarcane top and 2-5 parts of microbial strain liquid. The amount of the compound 
fertilizer organic matter is large than or equal to 55 weight parts, the total amount of NPK inorganic matters is large than or equal to 12 weight parts, the amount of the 
moisture is less than or equal to 25 weight parts, the effective 
viable count is large than or equal to 2 hundred million / 
gram, and the pH is 5.0-8.5. The preparation method comprises the following steps: fermenting twice by using microbial strains; adding inorganic 
porosity vermiculite, evenly mixing, and naturally 
drying so as to obtain the organic-
inorganic compound fertilizer. Biodegradable agricultural and industrial production waste water, waste 
slag and sugarcane top regeneration organic matters are fully utilized as the raw materials, thereby improving the acidity and basicity of soil, improving the cation exchange capability (CEC) of the soil, improving the utilization of fertilizer, promoting the growth of 
crop and increasing the yield of the 
crop. The organic-inorganic compound fertilizer has the advantages of good ecological benefits and 
circular economy benefits and can be used as an additional fertilizer for crops such as sugarcane, watermelon and the like.