NOVELTY - Oxamide granules is synthesized by subjecting ammonia gas in pre-ammonia absorption tank for ammonolysis reaction at 5-15 degrees C to obtain ammonia-methanol solution with 38.96-29.67% concentration, adding ammonia-methanol solution:dimethyl oxalate with lipid ratio of 2:1-5:1 into reaction kettle, allowing components to react to obtain solid dimethyl ester oxalate in which ammonia-methanol solution is sent into pressure reaction kettle through action of gravity, controlling temperature of pressure reaction kettle at 20-60 degrees C and performing reaction for 1-5 hours, and removing unreacted ammonia.    USE - Synthesis of oxamide granules for fertilizers.    ADVANTAGE - Synthesis process is safe, easy, simple, convenient, energy-saving, low-cost, and environment-friendly, has low equipment investment, high safety coefficient, product yield, and purity, no gas discharge into atmosphere which prevents pollution, and directly recycles uncondensed methanol gas.    DETAILED DESCRIPTION - Oxamide granules is synthesized by subjecting ammonia gas in pre-ammonia absorption tank for ammonolysis reaction at 5-15 degrees C to obtain ammonia-methanol solution with 38.96-29.67% concentration, adding ammonia-methanol solution:dimethyl oxalate with lipid ratio of 2:1-5:1 into reaction kettle, allowing components to react to obtain solid dimethyl ester oxalate in which ammonia-methanol solution is sent into pressure reaction kettle through action of gravity, controlling temperature of pressure reaction kettle at 20-60 degrees C and performing reaction for 1-5 hours, removing unreacted ammonia through vacuum pump, recovering material with methanol composition, maintaining amount of methanol to 2-40 mass%, stirring at 200-500 rpm, forming, heating to remove methanol, adding pure water in which water content of material is 1-20 mass%, and drying at 120-500 degrees C for 1-5 hours. An INDEPENDENT CLAIM is included for oxamide granules synthesis reactor (4) comprising stirring system, cooling system (5), external jacketed temperature control device (2), adjustable condenser (3) connected at top of reactor, and pre-ammonia absorption tank (7) at front end in which pre-ammonia absorption tank contains cooling system, condenser outlet, and tail gas absorbing tank (6) and particle forming and reaction processes are carried out in same oxamide granules synthesis reactor.    DESCRIPTION OF DRAWING(S) - The drawing shows an oxamide granules synthesis reactor.    External jacketed temperature control device (2)    Adjustable condenser (3)    Oxamide granules synthesis reactor (4)    Cooling system (5)    Tail gas absorbing tank (6)    Pre-ammonia absorption tank (7)