NOVELTY - Preparation of organic fertilizer includes mixing livestock and poultry manures or dead animal bodies and crop straw in reactor, and adjusting nitrogen ratio, carbon-phosphorus ratio and water content; adding organic fertilizer, decomposing to carry out rapid propagation of fermentation bacteria while generating heat, and using generated heat to increase reactor's temperature; controlling reactor's pressure and temperature, and sterilizing; and recovering pressure to atmospheric conditions, blowing air into reactor while stirring, adding fermentation culture, and adjusting moisture.    USE - Method for preparation of organic fertilizer (claimed).    ADVANTAGE - The method is simple, greatly increases production efficiency of organic fertilizer, can kill harmful microorganism, and it has low cost.    DETAILED DESCRIPTION - Preparation of organic fertilizer comprises:    (A) mixing livestock and poultry manures or dead animal bodies and crop straw, putting into reactor, and adjusting reactor's nitrogen ratio to 20:1-30:1, carbon-phosphorus ratio to 75-150:1 and water content to 45 -65%;    (B) adding organic fertilizer while continuously stirring, decomposing to carry out rapid propagation of fermentation bacteria while generating heat, and using generated heat to increase reactor's temperature to 60 degrees C or more;    (C) controlling reactor's pressure to 0.4 kg/cm and temperature to 80-130 degrees C through intelligent control system, and sterilizing fermentation raw material for 10-60 minutes to kill crop pests and diseases caused by pathogenic microorganisms and weed seeds;    (D) recovering pressure to atmospheric conditions, blowing air into reactor while stirring at 30-50 degrees C, adding fermentation culture, and adjusting moisture to 45-65%;    (E) placing into fermentation reaction tank, fermenting for 24-72 hours to carry out breeding large number of bacteria and rapid decomposition of fermentation materials;    (F) discharging fermentation material containing fermentation strains, stacking to carry out high temperature sterilizing, and turning or aerating to carry out secondary fermentation; and    (G) fermenting for a week or more.