NOVELTY - Method for preparing humic acid fertilizer, involves crushing mud carbon soil powder, mixing peat and molasses, adding mixed bacteria liquid to the mixture, adding mixture into reaction kettle, fermenting mixture, adding plant ash and lime to the mixture, stirring mixture, adding alginate, stirring, then adding turf, fermenting, adjusting pH, stopping reaction, taking the supernatant, emulsifying the reaction supernatant in emulsifying tank, adding e.g. urea, diethyl aminoethyl hexanoate and 5-sodium nitroguaiacolate, emulsifying mixture and adjusting pH.    USE - The method is useful for preparing humic acid fertilizer (all claimed).    ADVANTAGE - The method effectively improves humic acid, water soluble nitrogen, phosphorus and potassium nutrient content, enhances crops for nutrient elements of absorption efficiency, and reduces usage of fertilizer.    DETAILED DESCRIPTION - Method for preparing humic acid fertilizer, involves (a) obtaining raw materials comprising 20-25 pts. wt. peat powder, 10-15 pts. wt. plant ash, 1-5 pts. wt. lime, 5-12 pts. wt. urea, 10-15 pts. wt. sodium alginate, 5-10 pts. wt. potassium dihydrogen phosphate, 2-8 pts. wt. magnesium sulfate, 0.01-0.1 pts. wt. diethyl aminoethyl hexanoate and 0.01-0.03 pts. wt. 5-sodium nitroguaiacolate, (b) crushing mud carbon soil powder into 100 meshes, mixing peat and molasses in a mass ratio of 100:1, adding mixed bacteria liquid to the mixture until the water content is 80-90 wt.%, adding mixture into reaction kettle at 27-33 C and fermenting mixture for 5-6 days to obtain fermented mud, (c) adding plant ash and lime to the mixture, stirring mixture for 1 hour, adding alginate, stirring for 30 minutes, then adding turf, fermenting mixture at 60-70 C, adjusting pH of the mixture to 6-7.2 by de-ionized water, stopping reaction, taking the supernatant, where the mass ratio of the plant ash, slaked lime and de-ionized water is 10-15:5:40-50, and (c) emulsifying the reaction supernatant in emulsifying tank, adding urea, potassium dihydrogen phosphate, magnesium sulfate, diethyl aminoethyl hexanoate and 5-sodium nitroguaiacolate, emulsifying mixture for 10 minutes and adjusting pH of the mixture to 6-7.