NOVELTY - Preparing effervescent water-soluble fertilizer having enhanced geothermal efficacy comprises e.g. taking potassium humate as organic molecular material, fulvic acid and amino acid, and e.g. urea, ammonium sulfate, and potassium nitrate as macronutrient fertilizer, or Bacillus, saccharomycetes, Lactobacillus and actinomycetes as beneficial microorganism, mixing to obtain the intermediate product, adding intermediate product in weak alkaline material of e.g. potassium bicarbonate, or acidic material, mixing uniformly to obtain the product.    USE - The method is useful for preparing effervescent water-soluble fertilizer having enhanced geothermal efficacy (claimed).    ADVANTAGE - The method prepares fertilizer that can improve crop root growth environment, and overcomes problem of soil compaction, increased soil fertility and air permeability; uses acid alkali reaction released heat; and can shorten the fertilizer dissolution time. The fertilizer can increase soil temperature to prevent damage; and makes water temperature reach quickly for crop growing temperature, which is good for growth of crop in winter.    DETAILED DESCRIPTION - Preparing effervescent water-soluble fertilizer having enhanced geothermal efficacy comprises (i) taking potassium humate as organic molecular material, fulvic acid and amino acid, and urea, ammonium sulfate, industrial grade potassium dihydrogen phosphate, industrial-grade ammonium dihydrogen phosphate and potassium nitrate as the macronutrient fertilizer, disodium EDTA zinc, disodium EDTA iron, disodium EDTA copper, disodium EDTA manganese, boric acid or borax as trace elements, sodium carboxymethyl cellulose, soluble starch and polyacrylamide as polymeric water retention material, or Bacillus, saccharomycetes, Lactobacillus and actinomycetes as beneficial microorganism, mixing to obtain the intermediate product, and (ii) adding the intermediate product in weak alkaline material of potassium bicarbonate, magnesium bicarbonate, potassium carbonate and sodium carbonate, or acidic material of citric acid, oxalic acid and/or salicylic acid, and full mixing uniformly to obtain the product.