NOVELTY - An aztreonam is synthesized by (A) preparing tertbutyl ammonia, (B) preparing ammonia coarse product, and (C) preparing aztreonam. The step (C) comprises cooling absolute ethanol to 5-10 degrees C, adding the ammonia coarse product, and mixing solution; adding activated carbon, taking off carbon for 15-20 minutes and filtering; and rising temperature to 50-55 degrees C, cooling to room temperature and growing grain, filtering, cleaning with absolute methanol, drying, and obtaining aztreonam. The wt. ratio of aztreonam, absolute ethanol and activated carbon is 1:63.2-75. 9:0. 01-0.02.    USE - Method for synthesis of aztreonam (claimed).    ADVANTAGE - The method exhibits easy recovery and safer use of tetrahydrofuran. Yield is higher than 80%.    DETAILED DESCRIPTION - Aztreonam is synthesized by (A) preparing tertbutyl ammonia, (B) preparing ammonia coarse product, and (C) preparing aztreonam. The step (A) comprises adding ammonia intermediates and triethylamine to acetonitrile, mixing solution at room temperature, and adding dichloromethane, ice salt bath cooling to 0 degrees C, adding ceftazidime active ester by gradation, and reacting at 0-5 degrees C for 1-1. 5 hours; and using methylene chloride solution of trifluoroacetic acid to adjust reaction liquid pH to 2, precipitating solid, growing grain, filtering, and drying to obtain tertbutyl ammonia. The wt. ratio of acetonitrile, triethylamine, dichloromethane and ceftazidime active ester is 1:1.46-1.75:0.65-0.72:22-26:3-3.3. The step (B) comprises adding tertbutyl ammonia into purified water, adding concentrated hydrochloric acid, stirring and heating to 60 degrees C and refilling concentrated hydrochloric acid, reacting at 62-65 degrees C for 1-3 hours; adding purified water after reaction finished, stirring in room temperature, cooling and stirring with ice water bath; and filtering, cleaning, drying, and obtaining ammonia coarse product. The wt. ratio of tertbutyl ammonia, purified water and concentrated hydrochloric acid is 1:5. 26-6.31:1.39- 1.53. The step (C) comprises cooling absolute ethanol to 5-10 degrees C, adding the ammonia coarse product, and mixing solution; adding activated carbon, taking off carbon for 15-20 minutes and filtering; and rising temperature to 50-55 degrees C, cooling to room temperature and growing grain, filtering, cleaning with absolute methanol, drying, and obtaining aztreonam. The wt. ratio of aztreonam, absolute ethanol and activated carbon is 1:63.2-75. 9:0. 01-0.02.