NOVELTY - Preparing organic flower liquid fertilizer comprises mixing e.g. pig manure and human excrement, adjusting water content, transferring into a biogas fermenter, fermenting at high temperature, covering the digester to prevent the entry of sundries, adjusting nitrogen, phosphorus, potassium and trace element concentrations, controling the pH, taking out the fermentation broth, aerating and aging, sampling the major nutrient ingredients and analyzing, adding inorganic elements and adjusting the nutritional index, adjusting the pH with e.g. nitric acid, adding an essence, and mixing.    USE - The method is useful for preparing organic flower liquid fertilizer (claimed).    ADVANTAGE - The method: comprises pH adjusting step, which eliminates the inhibitors; and carries out addition of nutrients, thus promoting flower growth, development and required reproductive nutrition.    DETAILED DESCRIPTION - Preparing organic flower liquid fertilizer comprises mixing pig manure, dairy manure, chicken manure, human excrement and other animal manure for mixed fermentation, adjusting the water content by adding water, adjusting the solid content to be 6-10%, transferring into a biogas fermenter and fermenting for 30-60 days, where the fermentation period during summer is 30-32 days and during winter is 60-62 days, fermenting at high temperature, where gas is produced by normal ignition and stable combustion, and the concentration of the gas produced in summer is 6-8% and during winter is 8-10%, covering the digester to prevent the entry of sundries, adjusting nitrogen, phosphorus, potassium and trace element concentrations, controling the pH to be 6.3-6.5, taking out the fermentation broth, aerating and aging for 15-18 days, sampling the major nutrient ingredients and analyzing, adding inorganic elements and adjusting the nutritional index based on the requirement of flower nutrients, adjusting the pH of the liquid fertilizer to 6.3-6.5 using 6% nitric acid or phosphoric acid, adding an essence, mixing uniformly, and bottling.