NOVELTY - A seaweed synergia compound fertilizer is prepared using raw material containing 6 pts. wt., preferably 3-4 pts. wt. seaweed synergist, 32-62 pts. wt., preferably 12-50 pts. wt. urea melt, and 32-67 pts. wt., preferably 12-54 pts. wt. granulation material. The seaweed synergist is prepared by carrying out microbial fermentation of natural sea algae and extracting in presence of alkali. The solid content of seaweed synergist is 5-20 wt.%. The granulation material comprises monoammonium phosphate, potassium sulfate or chloride, bentonite and calcium powder.    USE - Seaweed synergia compound fertilizer (claimed).    ADVANTAGE - The seaweed synergia compound fertilizer is economically manufactured by simple process, and provides crop with high yield and reduced nutrient loss and secondary pollution.    DETAILED DESCRIPTION - A seaweed synergia compound fertilizer is prepared using raw material containing 6 pts. wt., preferably 3-4 pts. wt. seaweed synergist, 32-62 pts. wt., preferably 12-50 pts. wt. urea melt, and 32-67 pts. wt., preferably 12-54 pts. wt. granulation material. The seaweed synergist is prepared by carrying out microbial fermentation of natural algae and extracting in presence of alkali. The solid content of seaweed synergist is 5-20 wt.%. The granulation material comprises monoammonium phosphate or diammonium phosphate, potassium sulfate or potassium chloride, bentonite and calcium powder. An INDEPENDENT CLAIM is included for production of seaweed synergia compound fertilizer, which involves adding 800-1200 pts. wt. natural algae powder, 100-200 pts. wt. corn flour and 3-80 pts. wt. sugar into 3-50 wt.% water, adjusting pH to 6-8 using inorganic acid or inorganic alkali water solution to obtain natural seaweed fermentation material, mixing 0.1-2 pts. wt. effective microorganism-fermented liquid, 0.1-2 pts. wt. sugar and 0.5-20 pts. wt. water uniformly, adding obtained mixture in a sealed container for 20-30 hours, diluting obtained stock solution for 300-500 times, adding 10-100 pts. wt. obtained diluent, 800-1200 pts. wt. natural seaweed fermentation material, stirring uniformly, fermenting for 5-10 days, adding 800-1200 pts. wt. obtained fermented natural seaweed material into a reaction kettle, adding 10-50 pts. wt. 1-6 N aqueous solution of sodium hydroxide or sodium carbonate, stirring, extracting at 70-100 degrees C for 6-12 hours, filtering using filter press, evaporating, concentrating to obtain seaweed synergist, crushing diammonium phosphate or monoammonium phosphate, potassium sulfate or potassium chloride, bentonite and calcium powder until the particle size is more than 60 meshes, adding in drum granulator, mixing to obtain granulation material, adding seaweed synergist and urea in the weight ratio of 1-6: 32-62 into urea melting tank, adding water, melting at 95-125 degrees C to obtain urea melt, spraying urea melt on the granulation material in the rotary drum granulator, drying, sieving, cooling and packaging.