(2R,3S)-3-amino-2-methyl-4-oxo-1-azetidinesufonic acid is synthesized from L-threonine by esterification with methanol,ammonolysis of ester with CH3OH·NH3,protection of amino group with benzyl chloroformate, hydroxyl group by forming methanesulfonate with methane sulfonyl chloride,subsequently sulfonation with chlorosulfonic acid, cyclization under alkaline conditions and deprotection by hydrogenation. The product’s chemical structure is confirmed by the H-NMR, the purity is 98.2% by HPLC detection and the overall yield is 54.6%. The synthesis process is less demanding on equipment, with higher total yield and more suitable for industrial production.