NOVELTY - Production of waste seaweed algae liquid organic fertilizer includes washing waste seaweed algae, squeezing, drying, and crushing into powder; washing microalgae residue, and freeze-drying; mixing obtained powder and freeze-dried microalgae residue, adjusting pH with acetic acid-sodium acetate buffer suspension, adding cellulase, extracting, and inactivating enzyme; adjusting pH, adding pectinase, alginate gum and polysaccharide, extracting, and inactivating enzyme; and adjusting pH, adding protease protein, extracting, and inactivating enzyme to obtain algae residue hydrolysate.    USE - Method for production of waste seaweed algae liquid organic fertilizer (claimed).    ADVANTAGE - The method is environment-friendly, utilizes waste raw materials, and it has simple operation, short production period, and increased production process.    DETAILED DESCRIPTION - Production of waste seaweed algae liquid organic fertilizer comprises:    (A) washing waste seaweed algae, squeezing to carry out dehydration, drying, and crushing into uniform particle size powder;    (B) washing microalgae residue, and freeze-drying;    (C) mixing obtained powder and freeze-dried microalgae residue at mass ratio of 1-2:1, adding acetic acid-sodium acetate buffer suspension to adjust pH to 4.5-6, adding 2-2.5 wt.% cellulase to carry out enzymatic degradation, extracting to 45-55 degrees C for 48-72 hours, and inactivating enzyme for 4-8 minutes; adjusting pH to 3.5-5, adding 1-2 wt.% pectinase, alginate gum and polysaccharide, extracting to 40-50 degrees C for 48-72 hours, and inactivating enzyme; and adjusting pH to 5.5-6, adding 1-1.5 wt.% protease protein, extracting to 45-60 degrees C for 24-48 hours, and inactivating enzyme to obtain algae residue hydrolysate;    (D) subjecting to solid-liquid separation, collecting supernatant, and vacuum-concentrating until enzyme solution specific gravity is 1-1.2 g/mL; and    (E) extracting algae residue hydrolysate with ethanol for 12-24 hours, vacuum-concentrating supernatant until specific gravity is 1-1.2 g/mL, and mixing with obtained 5-10 wt.% enzyme solution.