NOVELTY - Solid material containing phosphate formed by processing glyphosate waste liquid, bentonite and attapulgite are mixed, dried, cooled, ground, sieved and mixed with activator protein, chitosan and humic acid salts to obtain mixture (A). The obtained mixture (A) is transferred to a drum granulator, and adhesive is added under conditions of rotary drum granulator to obtain wet soil conditioning agent particles having diameter of 2-4 mm. The obtained particles are dried at 100-110 degrees C to obtain acidic soil conditioning agent having moisture content of 5-8 wt.%.    USE - Preparation of acidic soil conditioning agent (claimed).    ADVANTAGE - The method efficiently provides high-purity acidic soil conditioning agent with high yield, without affecting the environment. The acidic soil conditioning agent regulates the pH of the soil and fixes heavy metal ion in soil.    DETAILED DESCRIPTION - Glyphosate waste liquid containing phosphate-containing solid is reacted with hydrogen sulfide gas at 5-50 degrees C for 2-5 hours at pressure of 0.1-0.5 MPa, to obtain precipitate containing heavy metal sulfides and precipitated mother liquor. The obtained precipitated mother liquor is heated at 60-120 degrees C in the pressure of 0.1-0.5 MPa, and oxidized for 1-6 hours, to obtain oxidized mother liquor precipitate. The obtained precipitate is mixed with limestone powder in the weight ratio of 1-6:0.1-0.5, and oxidized at 20-30 degrees C for 1-4 hours, to obtain phosphorus salt precipitate. The obtained precipitate is mixed with sodium chloride, and evaporative crystallization is carried out at 100-105 degrees C for 2-6 hours to separate sodium chloride crystals. The impurities are then removed and obtained phosphorus salt precipitate is mixed with water, stirred at 100-400 rpm, and repulping process is carried out. The obtained mixture is then subjected to solid-liquid separation, precipitated, dried at 95-105 degrees C for 1-5 hours to obtain solid material containing phosphate. The obtained phosphate-containing solid, bentonite and attapulgite are mixed in a mixer in the weight ratio of 30-45:20-40:20-30, dried at 95-105 degrees C, cooled to room temperature, ground, and sieved to powder having particle size of 250-300 mesh. To the resultant mixture, activator protein, chitosan and humic acid salts are added in the weight ratio of 0.01-0.1:0.1-0.5:5-10 and continuously mixed to obtain mixture (A). The obtained mixture (A) is transferred to a drum granulator, and adhesive is added under conditions of rotary drum granulator to obtain wet soil conditioning agent particles having diameter of 2-4 mm. The obtained particles are dried at 100-110 degrees C to obtain acidic soil conditioning agent having moisture content of 5-8 wt.%.